diff --git a/assets/config.php b/assets/config.php
index 702af5b0..357c4b26 100644
--- a/assets/config.php
+++ b/assets/config.php
@@ -19,6 +19,11 @@ return [
         // 
     ],
 
+    'central_domains' => [
+        '127.0.0.1',
+        'localhost',
+    ],
+
 
     'storage' => [
         'data_column' => 'data',
@@ -232,6 +237,6 @@ return [
      * Middleware pushed to the global middleware stack.
      */
     'global_middleware' => [ // todo get rid of this
-        Stancl\Tenancy\Middleware\InitializeTenancy::class,
+        // Stancl\Tenancy\Middleware\InitializeTenancy::class,
     ],
 ];
diff --git a/src/Contracts/Domain.php b/src/Contracts/Domain.php
new file mode 100644
index 00000000..ba7d2e2f
--- /dev/null
+++ b/src/Contracts/Domain.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Stancl\Tenancy\Contracts;
+
+/**
+ * @property-read Tenant $tenant
+ * 
+ * @see \Stancl\Tenancy\Database\Models\Domain
+ */
+interface Domain
+{
+    public function tenant();
+}
diff --git a/src/Database/Models/Domain.php b/src/Database/Models/Domain.php
index 2d07439f..db141e1f 100644
--- a/src/Database/Models/Domain.php
+++ b/src/Database/Models/Domain.php
@@ -8,7 +8,8 @@ use Stancl\Tenancy\Events\DomainCreated;
 use Stancl\Tenancy\Events\DomainDeleted;
 use Stancl\Tenancy\Events\DomainSaved;
 use Stancl\Tenancy\Events\DomainUpdated;
-use Stancl\Tenancy\Exceptions\DomainsOccupiedByOtherTenantException;
+use Stancl\Tenancy\Exceptions\DomainOccupiedByOtherTenantException;
+use Stancl\Tenancy\Contracts;
 
 /**
  * @property string $domain
@@ -16,7 +17,7 @@ use Stancl\Tenancy\Exceptions\DomainsOccupiedByOtherTenantException;
  *
  * @property-read Tenant $tenant
  */
-class Domain extends Model
+class Domain extends Model implements Contracts\Domain
 {
     public $guarded = [];
     public $casts = [
@@ -28,7 +29,7 @@ class Domain extends Model
         $ensureDomainIsNotOccupied = function (Domain $self) {
             if ($domain = Domain::where('domain', $self->domain)->first()) {
                 if ($domain->getKey() !== $self->getKey()) {
-                    throw new DomainsOccupiedByOtherTenantException;
+                    throw new DomainOccupiedByOtherTenantException($self->domain);
                 }
             }
         };
diff --git a/src/Exceptions/DomainOccupiedByOtherTenantException.php b/src/Exceptions/DomainOccupiedByOtherTenantException.php
new file mode 100644
index 00000000..00d42f3e
--- /dev/null
+++ b/src/Exceptions/DomainOccupiedByOtherTenantException.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Exceptions;
+
+use Exception;
+
+class DomainOccupiedByOtherTenantException extends Exception
+{
+    public function __construct($domain)
+    {
+        parent::__construct("The $domain domain is occupied by another tenant.");
+    }
+}
diff --git a/src/Exceptions/DomainsOccupiedByOtherTenantException.php b/src/Exceptions/DomainsOccupiedByOtherTenantException.php
deleted file mode 100644
index f6d59bda..00000000
--- a/src/Exceptions/DomainsOccupiedByOtherTenantException.php
+++ /dev/null
@@ -1,15 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Stancl\Tenancy\Exceptions;
-
-use Stancl\Tenancy\Contracts\TenantCannotBeCreatedException;
-
-class DomainsOccupiedByOtherTenantException extends TenantCannotBeCreatedException
-{
-    public function reason(): string
-    {
-        return "One or more of the tenant's domains are already occupied by another tenant.";
-    }
-}
diff --git a/src/Exceptions/NotASubdomainException.php b/src/Exceptions/NotASubdomainException.php
new file mode 100644
index 00000000..68c56a0c
--- /dev/null
+++ b/src/Exceptions/NotASubdomainException.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Stancl\Tenancy\Exceptions;
+
+use Exception;
+
+class NotASubdomainException extends Exception
+{
+    public function __construct(string $hostname)
+    {
+        parent::__construct("Hostname $hostname does not include a subdomain.");
+    }
+}
\ No newline at end of file
diff --git a/src/Middleware/IdentificationMiddleware.php b/src/Middleware/IdentificationMiddleware.php
new file mode 100644
index 00000000..dbc4e67a
--- /dev/null
+++ b/src/Middleware/IdentificationMiddleware.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Stancl\Tenancy\Middleware;
+
+use Stancl\Tenancy\Contracts\TenantCouldNotBeIdentifiedException;
+use Stancl\Tenancy\Contracts\TenantResolver;
+use Stancl\Tenancy\Tenancy;
+
+abstract class IdentificationMiddleware
+{
+    /** @var callable */
+    public static $onFail;
+
+    /** @var Tenancy */
+    protected $tenancy;
+
+    /** @var TenantResolver */
+    protected $resolver;
+
+    public function initializeTenancy($request, $next, ...$resolverArguments)
+    {
+        try {
+            $this->tenancy->initialize(
+                $this->resolver->resolve(...$resolverArguments)
+            );
+        } catch (TenantCouldNotBeIdentifiedException $e) {
+            $onFail = static::$onFail ?? function ($e) {
+                throw $e;
+            };
+
+            return $onFail($e, $request, $next);
+        }
+
+        return $next($request);
+    }
+}
\ No newline at end of file
diff --git a/src/Middleware/InitializeTenancy.php b/src/Middleware/InitializeTenancy.php
deleted file mode 100644
index c8b3bd2f..00000000
--- a/src/Middleware/InitializeTenancy.php
+++ /dev/null
@@ -1,45 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Stancl\Tenancy\Middleware;
-
-use Closure;
-use Stancl\Tenancy\Exceptions\TenantCouldNotBeIdentifiedException;
-
-class InitializeTenancy
-{
-    /** @var callable */
-    protected $onFail;
-
-    public function __construct(callable $onFail = null)
-    {
-        $this->onFail = $onFail ?? function ($e) {
-            throw $e;
-        };
-    }
-
-    /**
-     * Handle an incoming request.
-     *
-     * @param  \Illuminate\Http\Request  $request
-     * @param  \Closure  $next
-     * @return mixed
-     */
-    public function handle($request, Closure $next)
-    {
-        if (tenancy()->initialized) {
-            return $next($request);
-        }
-
-        if (! in_array($request->getHost(), config('tenancy.exempt_domains', []), true)) {
-            try {
-                tenancy()->init($request->getHost());
-            } catch (TenantCouldNotBeIdentifiedException $e) {
-                return ($this->onFail)($e, $request, $next);
-            }
-        }
-
-        return $next($request);
-    }
-}
diff --git a/src/Middleware/InitializeTenancyByDomain.php b/src/Middleware/InitializeTenancyByDomain.php
new file mode 100644
index 00000000..24a1abb7
--- /dev/null
+++ b/src/Middleware/InitializeTenancyByDomain.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Middleware;
+
+use Closure;
+use Stancl\Tenancy\Resolvers\DomainTenantResolver;
+use Stancl\Tenancy\Tenancy;
+
+class InitializeTenancyByDomain extends IdentificationMiddleware
+{
+    /** @var callable|null */
+    public static $onFail;
+
+    /** @var Tenancy */
+    protected $tenancy;
+
+    /** @var DomainTenantResolver */
+    protected $resolver;
+
+    public function __construct(Tenancy $tenancy, DomainTenantResolver $resolver)
+    {
+        $this->tenancy = $tenancy;
+        $this->resolver = $resolver;
+    }
+
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  \Closure  $next
+     * @return mixed
+     */
+    public function handle($request, Closure $next)
+    {
+        return $this->initializeTenancy(
+            $request, $next, $request->getHost()
+        );
+    }
+}
diff --git a/src/Middleware/InitializeTenancyByPath.php b/src/Middleware/InitializeTenancyByPath.php
index 7e5c92a8..3e4db04e 100644
--- a/src/Middleware/InitializeTenancyByPath.php
+++ b/src/Middleware/InitializeTenancyByPath.php
@@ -8,7 +8,7 @@ use Illuminate\Routing\Route;
 use Stancl\Tenancy\Resolvers\PathTenantResolver;
 use Stancl\Tenancy\Tenancy;
 
-class InitializeTenancyByPath
+class InitializeTenancyByPath extends IdentificationMiddleware
 {
     /** @var Tenancy */
     protected $tenancy;
@@ -27,14 +27,15 @@ class InitializeTenancyByPath
         /** @var Route $route */
         $route = $request->route();
 
+        // todo test the behavior described by the comment
         // Only initialize tenancy if tenant is the first parameter
         // We don't want to initialize tenancy if the tenant is
         // simply injected into some route controller action.
         if ($route->parameterNames()[0] === 'tenant') {
-            $this->tenancy->initialize(
-                $this->resolver->resolve($route)
+            return $this->initializeTenancy(
+                $request, $next, $route
             );
-        }
+        } // todo else case should probably throw exception about malformed route? or do we just leave that as the developer's responsibility?
 
         return $next($request);
     }
diff --git a/src/Middleware/InitializeTenancyBySubdomain.php b/src/Middleware/InitializeTenancyBySubdomain.php
new file mode 100644
index 00000000..2bad3c50
--- /dev/null
+++ b/src/Middleware/InitializeTenancyBySubdomain.php
@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Middleware;
+
+use Closure;
+use Illuminate\Http\Response;
+use Stancl\Tenancy\Exceptions\NotASubdomainException;
+
+class InitializeTenancyBySubdomain extends InitializeTenancyByDomain
+{
+    /** @var callable|null */
+    public static $onInvalidSubdomain;
+
+    /**
+     * The index of the subdomain fragment in the hostname
+     * split by `.`. 0 for first fragment, 1 if you prefix
+     * your subdomain fragments with `www`.
+     *
+     * @var int
+     */
+    public static $subdomainIndex = 0;
+
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  \Closure  $next
+     * @return mixed
+     */
+    public function handle($request, Closure $next)
+    {
+        $subdomain = $this->makeSubdomain($request->getHost());
+
+        // If a non-string, like a Response instance was returned
+        // from makeSubdomain() - due to NotASubDomainException
+        // being thrown, we abort by returning the value now.
+        if (! is_string($subdomain)) {
+            return $subdomain;
+        }
+
+        return $this->initializeTenancy(
+            $request, $next, $subdomain
+        );
+    }
+
+    /** @return string|Response|mixed */
+    protected function makeSubdomain(string $hostname)
+    {
+        $parts = explode('.', $hostname);
+
+        // If we're on localhost or an IP address, then we're not visiting a subdomain.
+        if (in_array(count($parts), [1, 4])) {
+            $handle = static::$onInvalidSubdomain ?? function ($e) {
+                throw $e;
+            };
+
+            return $handle(new NotASubdomainException($hostname));
+        }
+
+        // todo should we verify that the subdomain belongs to one of our central domains?
+        // if yes, then write a test for it.
+
+        return $parts[static::$subdomainIndex];
+    }
+}
diff --git a/src/Middleware/PreventAccessFromTenantDomains.php b/src/Middleware/PreventAccessFromTenantDomains.php
deleted file mode 100644
index 83afb31f..00000000
--- a/src/Middleware/PreventAccessFromTenantDomains.php
+++ /dev/null
@@ -1,75 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Stancl\Tenancy\Middleware;
-
-use Closure;
-use Illuminate\Routing\Route;
-use Illuminate\Support\Facades\Route as Router;
-
-/**
- * Prevent access from tenant domains to central routes and vice versa.
- */
-class PreventAccessFromTenantDomains
-{
-    /** @var callable */
-    protected $central404;
-
-    public function __construct(callable $central404 = null)
-    {
-        $this->central404 = $central404 ?? function () {
-            return 404;
-        };
-    }
-
-    /**
-     * Handle an incoming request.
-     *
-     * @param  \Illuminate\Http\Request  $request
-     * @param  \Closure  $next
-     * @return mixed
-     */
-    public function handle($request, Closure $next)
-    {
-        // If the route is universal, always let the request pass.
-        if ($this->routeHasMiddleware($request->route(), 'universal')) {
-            return $next($request);
-        }
-
-        // If the domain is not in exempt domains, it's a tenant domain.
-        // Tenant domains can't have routes without tenancy middleware.
-        $isExemptDomain = in_array($request->getHost(), config('tenancy.exempt_domains'));
-        $isTenantDomain = ! $isExemptDomain;
-
-        $isTenantRoute = $this->routeHasMiddleware($request->route(), 'tenancy');
-
-        if ($isTenantDomain && ! $isTenantRoute) { // accessing web routes from tenant domains
-            return redirect(config('tenancy.home_url'));
-        }
-
-        if ($isExemptDomain && $isTenantRoute) { // accessing tenant routes on web domains
-            return ($this->central404)($request, $next);
-        }
-
-        return $next($request);
-    }
-
-    public static function routeHasMiddleware(Route $route, $middleware): bool
-    {
-        if (in_array($middleware, $route->middleware(), true)) {
-            return true;
-        }
-
-        // Loop one level deep and check if the route's middleware
-        // groups have a `tenancy` middleware group inside them
-        $middlewareGroups = Router::getMiddlewareGroups();
-        foreach ($route->gatherMiddleware() as $inner) {
-            if (! $inner instanceof Closure && isset($middlewareGroups[$inner]) && in_array($middleware, $middlewareGroups[$inner], true)) {
-                return true;
-            }
-        }
-
-        return false;
-    }
-}
diff --git a/src/Resolvers/DomainTenantResolver.php b/src/Resolvers/DomainTenantResolver.php
index bfba9c5f..b00c1cc4 100644
--- a/src/Resolvers/DomainTenantResolver.php
+++ b/src/Resolvers/DomainTenantResolver.php
@@ -2,6 +2,7 @@
 
 namespace Stancl\Tenancy\Resolvers;
 
+use Stancl\Tenancy\Contracts\Domain;
 use Stancl\Tenancy\Contracts\Tenant;
 use Stancl\Tenancy\Contracts\TenantResolver;
 use Stancl\Tenancy\Exceptions\TenantCouldNotBeIdentifiedOnDomainException;
@@ -10,6 +11,7 @@ class DomainTenantResolver implements TenantResolver
 {
     public function resolve(...$args): Tenant
     {
+        /** @var Domain $domain */
         $domain = config('tenancy.domain_model')::where('domain', $args[0])->first();
 
         if ($domain) {
@@ -18,4 +20,4 @@ class DomainTenantResolver implements TenantResolver
 
         throw new TenantCouldNotBeIdentifiedOnDomainException($domain);
     }
-}
\ No newline at end of file
+}
diff --git a/src/Tenancy.php b/src/Tenancy.php
index afd063a1..bca42a5a 100644
--- a/src/Tenancy.php
+++ b/src/Tenancy.php
@@ -3,7 +3,7 @@
 namespace Stancl\Tenancy;
 
 use Stancl\Tenancy\Contracts\TenancyBootstrapper;
-use Stancl\Tenancy\Database\Models\Tenant;
+use Stancl\Tenancy\Database\Models\Tenant; // todo contract
 
 class Tenancy
 {
@@ -18,6 +18,11 @@ class Tenancy
 
     public function initialize(Tenant $tenant): void
     {
+        // todo the id is something that should be on the contract, with a method
+        if ($this->initialized && $this->tenant->id === $tenant->id) {
+            return;
+        }
+
         $this->tenant = $tenant;
 
         $this->initialized = true;
diff --git a/tests/v3/DomainTest.php b/tests/v3/DomainTest.php
index efb72a1a..898f7be5 100644
--- a/tests/v3/DomainTest.php
+++ b/tests/v3/DomainTest.php
@@ -2,10 +2,12 @@
 
 namespace Stancl\Tenancy\Tests\v3;
 
+use Illuminate\Support\Facades\Route;
 use Stancl\Tenancy\Database\Models;
 use Stancl\Tenancy\Database\Models\Concerns\HasDomains;
-use Stancl\Tenancy\Exceptions\DomainsOccupiedByOtherTenantException;
+use Stancl\Tenancy\Exceptions\DomainOccupiedByOtherTenantException;
 use Stancl\Tenancy\Exceptions\TenantCouldNotBeIdentifiedOnDomainException;
+use Stancl\Tenancy\Middleware\InitializeTenancyByDomain;
 use Stancl\Tenancy\Resolvers\DomainTenantResolver;
 use Stancl\Tenancy\Tests\TestCase;
 
@@ -15,6 +17,14 @@ class DomainTest extends TestCase
     {
         parent::setUp();
 
+        Route::group([
+            'middleware' => InitializeTenancyByDomain::class,
+        ], function () {
+            Route::get('/foo/{a}/{b}', function ($a, $b) {
+                return "$a + $b";
+            });
+        });
+
         config(['tenancy.tenant_model' => Tenant::class]);
     }
 
@@ -46,7 +56,7 @@ class DomainTest extends TestCase
 
         $tenant2 = Tenant::create();
 
-        $this->expectException(DomainsOccupiedByOtherTenantException::class);
+        $this->expectException(DomainOccupiedByOtherTenantException::class);
         $tenant2->domains()->create([
             'domain' => 'foo.localhost',
         ]);
@@ -61,29 +71,40 @@ class DomainTest extends TestCase
     }
 
     /** @test */
-    public function tenancy_is_initialized_prior_to_controller_constructors()
+    public function tenant_can_be_identified_by_domain()
     {
-        // todo
-        $this->assertTrue(app('tenancy_was_initialized_in_constructor'));
+        $tenant = Tenant::create([
+            'id' => 'acme',
+        ]);
+
+        $tenant->domains()->create([
+            'domain' => 'foo.localhost',
+        ]);
+
+        $this->assertFalse(tenancy()->initialized);
+
+        $this
+            ->get('http://foo.localhost/foo/abc/xyz')
+            ->assertSee('abc + xyz');
+
         $this->assertTrue(tenancy()->initialized);
         $this->assertSame('acme', tenant('id'));
     }
+
+    /** @test */
+    public function onfail_logic_can_be_customized()
+    {
+        InitializeTenancyByDomain::$onFail = function () {
+            return 'foo';
+        };
+
+        $this
+            ->get('http://foo.localhost/foo/abc/xyz')
+            ->assertSee('foo');
+    }
 }
 
 class Tenant extends Models\Tenant
 {
     use HasDomains;
 }
-
-class TestController
-{
-    public function __construct()
-    {
-        app()->instance('tenancy_was_initialized_in_constructor', tenancy()->initialized);
-    }
-
-    public function index()
-    {
-        return 'foo';
-    }
-}
\ No newline at end of file
diff --git a/tests/v3/PathIdentificationTest.php b/tests/v3/PathIdentificationTest.php
index cddc51f5..dc440b2b 100644
--- a/tests/v3/PathIdentificationTest.php
+++ b/tests/v3/PathIdentificationTest.php
@@ -10,13 +10,6 @@ use Stancl\Tenancy\Tests\TestCase;
 
 class PathIdentificationTest extends TestCase
 {
-    public function getEnvironmentSetup($app)
-    {
-        parent::getEnvironmentSetUp($app);
-
-        config(['tenancy.global_middleware' => []]);
-    }
-
     public function setUp(): void
     {
         parent::setUp();
@@ -28,8 +21,6 @@ class PathIdentificationTest extends TestCase
             Route::get('/foo/{a}/{b}', function ($a, $b) {
                 return "$a + $b";
             });
-
-            Route::get('/bar', [TestController::class, 'index']);
         });
     }
 
@@ -42,8 +33,7 @@ class PathIdentificationTest extends TestCase
 
         $this->assertFalse(tenancy()->initialized);
 
-        $this
-            ->get('/acme/foo/abc/xyz');
+        $this->get('/acme/foo/abc/xyz');
 
         $this->assertTrue(tenancy()->initialized);
         $this->assertSame('acme', tenant('id'));
@@ -77,4 +67,16 @@ class PathIdentificationTest extends TestCase
          
         $this->assertFalse(tenancy()->initialized);
     }
+
+    /** @test */
+    public function onfail_logic_can_be_customized()
+    {
+        InitializeTenancyByPath::$onFail = function () {
+            return 'foo';
+        };
+
+        $this
+            ->get('/acme/foo/abc/xyz')
+            ->assertSee('foo');
+    }
 }
diff --git a/tests/v3/SubdomainIdentificationTest.php b/tests/v3/SubdomainIdentificationTest.php
deleted file mode 100644
index e69de29b..00000000
diff --git a/tests/v3/SubdomainTest.php b/tests/v3/SubdomainTest.php
new file mode 100644
index 00000000..38b3054e
--- /dev/null
+++ b/tests/v3/SubdomainTest.php
@@ -0,0 +1,101 @@
+<?php
+
+namespace Stancl\Tenancy\Tests\v3;
+
+use Illuminate\Support\Facades\Route;
+use Stancl\Tenancy\Database\Models;
+use Stancl\Tenancy\Database\Models\Concerns\HasDomains;
+use Stancl\Tenancy\Exceptions\NotASubdomainException;
+use Stancl\Tenancy\Middleware\InitializeTenancyBySubdomain;
+use Stancl\Tenancy\Tests\TestCase;
+
+class SubdomainTest extends TestCase
+{
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        Route::group([
+            'middleware' => InitializeTenancyBySubdomain::class,
+        ], function () {
+            Route::get('/foo/{a}/{b}', function ($a, $b) {
+                return "$a + $b";
+            });
+        });
+
+        config(['tenancy.tenant_model' => Tenant::class]);
+    }
+
+    /** @test */
+    public function tenant_can_be_identified_by_subdomain()
+    {
+        $tenant = Tenant::create([
+            'id' => 'acme',
+        ]);
+
+        $tenant->domains()->create([
+            'domain' => 'foo',
+        ]);
+
+        $this->assertFalse(tenancy()->initialized);
+
+        $this
+            ->get('http://foo.localhost/foo/abc/xyz')
+            ->assertSee('abc + xyz');
+
+        $this->assertTrue(tenancy()->initialized);
+        $this->assertSame('acme', tenant('id'));
+    }
+
+    /** @test */
+    public function onfail_logic_can_be_customized()
+    {
+        InitializeTenancyBySubdomain::$onFail = function () {
+            return 'foo';
+        };
+
+        $this
+            ->get('http://foo.localhost/foo/abc/xyz')
+            ->assertSee('foo');
+    }
+
+    /** @test */
+    public function localhost_is_not_a_valid_subdomain()
+    {
+        $this->expectException(NotASubdomainException::class);
+
+        $this
+            ->withoutExceptionHandling()
+            ->get('http://localhost/foo/abc/xyz');
+    }
+
+    /** @test */
+    public function ip_address_is_not_a_valid_subdomain()
+    {
+        $this->expectException(NotASubdomainException::class);
+
+        $this
+            ->withoutExceptionHandling()
+            ->get('http://127.0.0.1/foo/abc/xyz');
+    }
+
+    /** @test */
+    public function oninvalidsubdomain_logic_can_be_customized()
+    {
+        // in this case, we need to return a response instance
+        // since a string would be treated as the subdomain
+        InitializeTenancyBySubdomain::$onInvalidSubdomain = function () {
+            return response('foo custom invalid subdomain handler');
+        };
+
+        $this
+            ->withoutExceptionHandling()
+            ->get('http://127.0.0.1/foo/abc/xyz')
+            ->assertSee('foo custom invalid subdomain handler');
+    }
+}
+
+class Tenant extends Models\Tenant
+{
+    use HasDomains;
+}