diff --git a/README.md b/README.md
index 9bbcf93..6615313 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,10 @@ $routes = new RouteGroup(
     ],
     patterns: ['page' => '.*'],
 );
+
+$router = new Router($routes, $container);
+
+$response = $router->handle($request);
 ```
 
 #### Path
@@ -65,7 +69,7 @@ new RouteGroup([
 ]);
 ```
 
-If you have a parameter that is used in multiple routes, you can define it in the `RouteGroup`. It will be used in all the routes of the group:
+If you have a parameter that is used in multiple routes, you can define it inside the `RouteGroup`. It will be used in all the routes of the group:
 
 ```php
 new RouteGroup(
diff --git a/src/RouteGroup.php b/src/RouteGroup.php
index f765790..61c4888 100644
--- a/src/RouteGroup.php
+++ b/src/RouteGroup.php
@@ -7,7 +7,7 @@
 final class RouteGroup
 {
     /**
-     * @param Route[] $routes
+     * @param array<Route|RouteGroup> $routes
      * @param mixed[] $middlewares
      * @param mixed[] $conditions
      * @param array<string, string> $patterns
diff --git a/src/Router.php b/src/Router.php
index 4d772f1..d5b2c5c 100644
--- a/src/Router.php
+++ b/src/Router.php
@@ -13,33 +13,37 @@
 };
 use Psr\Http\Server\{RequestHandlerInterface, MiddlewareInterface};
 
-final readonly class Router implements RequestHandlerInterface
+final class Router implements RequestHandlerInterface
 {
+    private int $conditionIndex = 0;
+    private int $middlewareIndex = 0;
+    private int $routeIndex = 0;
+
     public function __construct(
-        private RouteGroup $routeGroup,
-        private ContainerInterface $container,
-        private mixed $fallback = null,
+        private readonly RouteGroup $routeGroup,
+        private readonly ContainerInterface $container,
+        private readonly mixed $fallback = null,
     ) {
     }
 
     public function handle(ServerRequestInterface $request): ResponseInterface
     {
-        if ($this->routeGroup->conditions !== []) {
+        if (isset($this->routeGroup->conditions[$this->conditionIndex])) {
             return $this->executeConditions($request);
         }
 
-        if ($this->routeGroup->middlewares !== []) {
+        if (isset($this->routeGroup->middlewares[$this->middlewareIndex])) {
             return $this->executeMiddlewares($request);
         }
 
-        return $this->executeRoutes($request);
+        return $this->executeRoutables($request);
     }
 
     private function executeConditions(ServerRequestInterface $request): ResponseInterface
     {
         $newRequest = $request;
-        while ($this->routeGroup->conditions !== []) {
-            $matchedParams = $this->callConditionHandler(array_shift($this->routeGroup->conditions), $newRequest);
+        while (isset($this->routeGroup->conditions[$this->conditionIndex])) {
+            $matchedParams = $this->executeCondition($this->routeGroup->conditions[$this->conditionIndex++], $newRequest);
             if ($matchedParams === false) {
                 return $this->fallback($request);
             }
@@ -55,12 +59,12 @@ private function executeConditions(ServerRequestInterface $request): ResponseInt
     /**
      * @return array<string, mixed>|false
      */
-    private function callConditionHandler(mixed $callback, ServerRequestInterface $request): array|false
+    private function executeCondition(mixed $callback, ServerRequestInterface $request): array|false
     {
         $handler = $this->resolveCallback($callback);
 
         if (!is_callable($handler)) {
-            throw new InvalidRoute('Condition handler cannot be called.');
+            throw new InvalidRoute("Condition callback is not callable.");
         }
 
         $result = $handler($request);
@@ -74,27 +78,30 @@ private function callConditionHandler(mixed $callback, ServerRequestInterface $r
 
     private function executeMiddlewares(ServerRequestInterface $request): ResponseInterface
     {
-        return $this->callMiddlewareHandler(array_shift($this->routeGroup->middlewares), $request);
-    }
-
-    private function callMiddlewareHandler(mixed $callback, ServerRequestInterface $request): ResponseInterface
-    {
-        $handler = $this->resolveCallback($callback);
+        $middleware = $this->routeGroup->middlewares[$this->middlewareIndex++];
+        $handler = $this->resolveCallback($middleware);
 
         if ($handler instanceof MiddlewareInterface) {
             return $handler->process($request, $this);
         }
 
         if (!is_callable($handler)) {
-            throw new InvalidRoute('Middleware handler cannot be called.');
+            throw new InvalidRoute("Middleware callback is not callable.");
         }
 
         return $this->processResponse($handler($request, $this));
     }
 
-    private function executeRoutes(ServerRequestInterface $request): ResponseInterface
+    private function executeRoutables(ServerRequestInterface $request): ResponseInterface
     {
-        foreach ($this->routeGroup->routes as $route) {
+        while (isset($this->routeGroup->routes[$this->routeIndex])) {
+            $route = $this->routeGroup->routes[$this->routeIndex++];
+
+            if ($route instanceof RouteGroup) {
+                $newRouter = new Router($route, $this->container, $this->handle(...));
+                return $newRouter->handle($request);
+            }
+
             $matchedParams = $route->match($request, $this->routeGroup->patterns);
             if ($matchedParams === false) {
                 continue;
@@ -124,7 +131,7 @@ private function callRouteHandler(mixed $callback, ServerRequestInterface $reque
         }
 
         if (!is_callable($handler)) {
-            throw new InvalidRoute('Route handler cannot be called.');
+            throw new InvalidRoute("Route callback is not callable.");
         }
 
         return $this->processResponse($handler($request, $this));
diff --git a/tests/RouterConditionTest.php b/tests/RouteGroupConditionTest.php
similarity index 80%
rename from tests/RouterConditionTest.php
rename to tests/RouteGroupConditionTest.php
index 8fd1b2e..f080a9a 100644
--- a/tests/RouterConditionTest.php
+++ b/tests/RouteGroupConditionTest.php
@@ -6,14 +6,14 @@
 
 use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\{ResponseInterface, ServerRequestInterface};
-use IngeniozIT\Router\{InvalidRoute, RouteGroup, Router, Route};
+use IngeniozIT\Router\{Router, RouteGroup, Route, InvalidRoute};
 use IngeniozIT\Http\Message\UriFactory;
 use Closure;
 
 /**
  * @SuppressWarnings(PHPMD.StaticAccess)
  */
-final class RouterConditionTest extends TestCase
+final class RouteGroupConditionTest extends TestCase
 {
     use PsrTrait;
 
@@ -58,6 +58,25 @@ public static function providerConditions(): array
         ];
     }
 
+    public function testCanHaveMultipleConditions(): void
+    {
+        $routeGroup = new RouteGroup(
+            routes: [
+                Route::get(path: '/', callback: static fn(): ResponseInterface => self::response('TEST2')),
+            ],
+            conditions: [
+                static fn(): array => [],
+                static fn(): bool => false,
+            ],
+        );
+        $request = self::serverRequest('GET', '/');
+
+        $response = $this->router($routeGroup, static fn(): ResponseInterface =>
+        self::response('TEST'))->handle($request);
+
+        self::assertEquals('TEST', (string)$response->getBody());
+    }
+
     /**
      * @dataProvider providerInvalidConditions
      */
diff --git a/tests/RouterMiddlewareTest.php b/tests/RouteGroupMiddlewareTest.php
similarity index 77%
rename from tests/RouterMiddlewareTest.php
rename to tests/RouteGroupMiddlewareTest.php
index df0b55b..905701b 100644
--- a/tests/RouterMiddlewareTest.php
+++ b/tests/RouteGroupMiddlewareTest.php
@@ -4,14 +4,15 @@
 
 namespace IngeniozIT\Router\Tests;
 
+use Exception;
 use PHPUnit\Framework\TestCase;
-use Psr\Http\Message\{ResponseInterface, ServerRequestInterface};
 use IngeniozIT\Router\{
-    InvalidRoute,
-    RouteGroup,
     Router,
+    RouteGroup,
     Route,
+    InvalidRoute,
 };
+use Psr\Http\Message\{ResponseInterface, ServerRequestInterface};
 use IngeniozIT\Router\Tests\Fakes\TestMiddleware;
 use Psr\Http\Server\RequestHandlerInterface;
 use IngeniozIT\Http\Message\UriFactory;
@@ -20,7 +21,7 @@
 /**
  * @SuppressWarnings(PHPMD.StaticAccess)
  */
-final class RouterMiddlewareTest extends TestCase
+final class RouteGroupMiddlewareTest extends TestCase
 {
     use PsrTrait;
 
@@ -68,6 +69,25 @@ public static function providerMiddlewares(): array
         ];
     }
 
+    public function testCanHaveMultipleMiddlewares(): void
+    {
+        $routeGroup = new RouteGroup(
+            routes: [
+                Route::get(path: '/', callback: static fn(): ResponseInterface => self::response('TEST2')),
+            ],
+            middlewares: [
+                static fn(ServerRequestInterface $request, RequestHandlerInterface $handler) => $handler->handle($request),
+                static fn(ServerRequestInterface $request, RequestHandlerInterface $handler) => throw new Exception(''),
+            ],
+        );
+        $request = self::serverRequest('GET', '/');
+
+        self::expectException(Exception::class);
+        $response = $this->router($routeGroup)->handle($request);
+
+        self::assertEquals('TEST', (string) $response->getBody());
+    }
+
     /**
      * @dataProvider providerInvalidMiddlewares
      */
diff --git a/tests/RouteTest.php b/tests/RouteTest.php
index c11bd9b..a12e19a 100644
--- a/tests/RouteTest.php
+++ b/tests/RouteTest.php
@@ -17,7 +17,7 @@ final class RouteTest extends TestCase
     /**
      * @dataProvider providerMethodsAndRoutes
      */
-    public function testMatchesRequestBasedOnMethod(string $method, callable $routeCallable): void
+    public function testMatchesRequestsBasedOnMethod(string $method, callable $routeCallable): void
     {
         /** @var Route $route */
         $route = $routeCallable('/', 'foo');
@@ -89,7 +89,7 @@ public function testCanMatchSomeMethods(): void
         self::assertSame(false, $putResult);
     }
 
-    public function testMatchesRequestBasedOnPath(): void
+    public function testMatchesRequestsBasedOnPath(): void
     {
         $route = Route::get('/foo', 'foo');
         $matchingRequest = self::serverRequest('GET', '/foo');
@@ -133,9 +133,20 @@ public function testCanUseCustomPatterns(Route $route): void
     public static function providerRoutePatterns(): array
     {
         return [
-            'from the path' => [Route::get('/foo/{bar:\d+}/{baz:\d+}', 'foo')],
-            'from the patterns parameter' => [Route::get('/foo/{bar}/{baz}', 'foo', patterns: ['bar' => '\d+', 'baz' => '\d+'])],
-            'path takes precedence over the patterns parameter' => [Route::get('/foo/{bar:\d+}/{baz:\d+}', 'foo', patterns: ['bar' => '[a-z]+', 'baz' => '\d+'])],
+            'patterns inside the path' => [Route::get(
+                path: '/foo/{bar:\d+}/{baz:\d+}',
+                callback: 'foo'
+            )],
+            'patterns as a parameter' => [Route::get(
+                path: '/foo/{bar}/{baz}',
+                callback: 'foo',
+                patterns: ['bar' => '\d+', 'baz' => '\d+'],
+            )],
+            'path takes precendence over parameters' => [Route::get(
+                path: '/foo/{bar:\d+}/{baz:\d+}',
+                callback: 'foo',
+                patterns: ['bar' => '[a-z]+', 'baz' => '\d+'],
+            )],
         ];
     }
 
diff --git a/tests/SubGroupTest.php b/tests/SubGroupTest.php
new file mode 100644
index 0000000..cecc6a5
--- /dev/null
+++ b/tests/SubGroupTest.php
@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace IngeniozIT\Router\Tests;
+
+use PHPUnit\Framework\TestCase;
+use IngeniozIT\Router\{Router, RouteGroup, Route};
+use Closure;
+
+/**
+ * @SuppressWarnings(PHPMD.StaticAccess)
+ */
+class SubGroupTest extends TestCase
+{
+    use PsrTrait;
+
+    private function router(RouteGroup $routeGroup, ?Closure $fallback = null): Router
+    {
+        return new Router($routeGroup, self::container(), $fallback);
+    }
+
+    public function testCanHaveSubGroups(): void
+    {
+        $routeGroup = new RouteGroup(
+            routes: [
+                new RouteGroup(
+                    routes: [
+                        Route::get(path: '/sub', callback: static fn() => 'TEST'),
+                    ],
+                ),
+            ],
+        );
+        $request = self::serverRequest('GET', '/sub');
+
+        $response = $this->router($routeGroup)->handle($request);
+
+        self::assertEquals('TEST', (string)$response->getBody());
+    }
+
+    public function testCanHandleARouteAfterASubGroup(): void
+    {
+        $routeGroup = new RouteGroup(
+            routes: [
+                new RouteGroup(
+                    routes: [
+                        Route::get(path: '/sub', callback: static fn() => 'TEST'),
+                    ],
+                ),
+                Route::get(path: '/after-sub', callback: static fn() => 'TEST2'),
+            ],
+        );
+        $request = self::serverRequest('GET', '/after-sub');
+
+        $response = $this->router($routeGroup)->handle($request);
+
+        self::assertEquals('TEST2', (string)$response->getBody());
+    }
+}