diff --git a/src/SAML11/Constants.php b/src/SAML11/Constants.php
index 9b492ac..87bb37e 100644
--- a/src/SAML11/Constants.php
+++ b/src/SAML11/Constants.php
@@ -81,7 +81,6 @@ class Constants extends \SimpleSAML\XMLSecurity\Constants
      */
     public const NAMEID_UNSPECIFIED = 'urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified';
 
-
     /**
      * Windows Domain Qualifier Name NameID format.
      */
@@ -102,4 +101,80 @@ class Constants extends \SimpleSAML\XMLSecurity\Constants
      * The namespace for the SAML 1.1 protocol.
      */
     public const NS_SAMLP = 'urn:oasis:names:tc:SAML:1.0:protocol';
+
+    /**
+     * The SAML responder or SAML authority is able to process the request but has chosen not to respond.
+     * This status code MAY be used when there is concern about the security context of the request message or
+     * the sequence of request messages received from a particular requester.
+     *
+     * Second-level status code.
+     */
+    public const STATUS_REQUEST_DENIED = 'samlp:RequestDenied';
+
+    /**
+     * The SAML responder cannot process any requests with the protocol version specified in the request.
+     *
+     * Second-level status code.
+     */
+    public const STATUS_REQUEST_VERSION_DEPRECATED = 'samlp:RequestVersionDeprecated';
+
+    /**
+     * The SAML responder cannot process the request because the protocol version specified in the request message
+     * is a major upgrade from the highest protocol version supported by the responder.
+     *
+     * Second-level status code.
+     */
+    public const STATUS_REQUEST_VERSION_TOO_HIGH = 'samlp:RequestVersionTooHigh';
+
+    /**
+     * The SAML responder cannot process the request because the protocol version specified in the request message
+     * is too low.
+     *
+     * Second-level status code.
+     */
+    public const STATUS_REQUEST_VERSION_TOO_LOW = 'samlp:RequestVersionTooLow';
+
+    /**
+     * The request could not be performed due to an error on the part of the requester.
+     *
+     * Top-level status code.
+     */
+    public const STATUS_REQUESTER = 'samlp:Requester';
+
+    /**
+     * The resource value provided in the request message is invalid or unrecognized.
+     *
+     * Second-level status code.
+     */
+    public const STATUS_RESOURCE_NOT_RECOGNIZED = 'samlp:ResourceNotRecognized';
+
+    /**
+     * The request could not be performed due to an error on the part of the SAML responder or SAML authority.
+     *
+     * Top-level status code.
+     */
+    public const STATUS_RESPONDER = 'samlp:Responder';
+
+    /**
+     * Top-level status code indicating successful processing of the request.
+     * The request succeeded. Additional information MAY be returned in the <StatusMessage>
+     * and/or <StatusDetail> elements.
+     *
+     * Top-level status code.
+     */
+    public const STATUS_SUCCESS = 'samlp:Success';
+
+    /**
+     * The response message would contain more elements than the SAML responder is able to return.
+     *
+     * Second-level status code.
+     */
+    public const STATUS_TOO_MANY_RESPONSES = 'samlp:TooManyResponses';
+
+    /**
+     * The SAML responder could not process the request because the version of the request message was incorrect.
+     *
+     * Top-level status code.
+     */
+    public const STATUS_VERSION_MISMATCH = 'samlp:VersionMismatch';
 }
diff --git a/src/SAML11/XML/samlp/AbstractStatusCodeType.php b/src/SAML11/XML/samlp/AbstractStatusCodeType.php
new file mode 100644
index 0000000..d3e0bb2
--- /dev/null
+++ b/src/SAML11/XML/samlp/AbstractStatusCodeType.php
@@ -0,0 +1,100 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\SAML11\XML\samlp;
+
+use DOMElement;
+use SimpleSAML\Assert\Assert;
+use SimpleSAML\SAML11\Constants as C;
+use SimpleSAML\XML\Exception\InvalidDOMElementException;
+
+/**
+ * SAML StatusCode data type.
+ *
+ * @package simplesamlphp/saml11
+ */
+abstract class AbstractStatusCodeType extends AbstractSamlpElement
+{
+    /**
+     * Initialize a samlp:StatusCode
+     *
+     * @param string $Value
+     * @param \SimpleSAML\SAML11\XML\samlp\StatusCode[] $subCodes
+     */
+    final public function __construct(
+        protected string $Value = C::STATUS_SUCCESS,
+        protected array $subCodes = [],
+    ) {
+        Assert::validQName($Value);
+        Assert::maxCount($subCodes, C::UNBOUNDED_LIMIT);
+        Assert::allIsInstanceOf($subCodes, StatusCode::class);
+    }
+
+
+    /**
+     * Collect the Value
+     *
+     * @return string
+     */
+    public function getValue(): string
+    {
+        return $this->Value;
+    }
+
+
+    /**
+     * Collect the subcodes
+     *
+     * @return \SimpleSAML\SAML11\XML\samlp\StatusCode[]
+     */
+    public function getSubCodes(): array
+    {
+        return $this->subCodes;
+    }
+
+
+    /**
+     * Convert XML into a StatusCode
+     *
+     * @param \DOMElement $xml The XML element we should load
+     * @return static
+     *
+     * @throws \SimpleSAML\XML\Exception\InvalidDOMElementException
+     *   if the qualified name of the supplied element is wrong
+     * @throws \SimpleSAML\XML\Exception\MissingAttributeException
+     *   if the supplied element is missing one of the mandatory attributes
+     */
+    public static function fromXML(DOMElement $xml): static
+    {
+        Assert::same($xml->localName, 'StatusCode', InvalidDOMElementException::class);
+        Assert::same($xml->namespaceURI, StatusCode::NS, InvalidDOMElementException::class);
+
+        $Value = self::getAttribute($xml, 'Value');
+        $subCodes = StatusCode::getChildrenOfClass($xml);
+
+        return new static(
+            $Value,
+            $subCodes,
+        );
+    }
+
+
+    /**
+     * Convert this StatusCode to XML.
+     *
+     * @param \DOMElement|null $parent The element we should append this StatusCode to.
+     * @return \DOMElement
+     */
+    public function toXML(DOMElement $parent = null): DOMElement
+    {
+        $e = $this->instantiateParentElement($parent);
+        $e->setAttribute('Value', $this->getValue());
+
+        foreach ($this->getSubCodes() as $subCode) {
+            $subCode->toXML($e);
+        }
+
+        return $e;
+    }
+}
diff --git a/src/SAML11/XML/samlp/StatusCode.php b/src/SAML11/XML/samlp/StatusCode.php
new file mode 100644
index 0000000..9f41257
--- /dev/null
+++ b/src/SAML11/XML/samlp/StatusCode.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\SAML11\XML\samlp;
+
+/**
+ * Class representing a saml:StatusCode element.
+ *
+ * @package simplesamlphp/saml11
+ */
+final class StatusCode extends AbstractStatusCodeType
+{
+}
diff --git a/tests/resources/xml/samlp_StatusCode.xml b/tests/resources/xml/samlp_StatusCode.xml
new file mode 100644
index 0000000..f44b818
--- /dev/null
+++ b/tests/resources/xml/samlp_StatusCode.xml
@@ -0,0 +1,3 @@
+<samlp:StatusCode xmlns:samlp="urn:oasis:names:tc:SAML:1.0:protocol" Value="samlp:Responder">
+  <samlp:StatusCode Value="samlp:RequestDenied"/>
+</samlp:StatusCode>
diff --git a/tests/src/SAML11/XML/samlp/StatusCodeTest.php b/tests/src/SAML11/XML/samlp/StatusCodeTest.php
new file mode 100644
index 0000000..617e34a
--- /dev/null
+++ b/tests/src/SAML11/XML/samlp/StatusCodeTest.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\Test\SAML11\XML\samlp;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\TestCase;
+use SimpleSAML\SAML11\Constants as C;
+use SimpleSAML\SAML11\XML\samlp\AbstractSamlpElement;
+use SimpleSAML\SAML11\XML\samlp\StatusCode;
+use SimpleSAML\XML\DOMDocumentFactory;
+use SimpleSAML\XML\TestUtils\SchemaValidationTestTrait;
+use SimpleSAML\XML\TestUtils\SerializableElementTestTrait;
+
+use function dirname;
+use function strval;
+
+/**
+ * Class \SimpleSAML\SAML11\XML\samlp\StatusCodeTest
+ *
+ * @package simplesamlphp/saml11
+ */
+#[Group('samlp')]
+#[CoversClass(StatusCode::class)]
+#[CoversClass(AbstractSamlpElement::class)]
+final class StatusCodeTest extends TestCase
+{
+    use SchemaValidationTestTrait;
+    use SerializableElementTestTrait;
+
+
+    /**
+     */
+    public static function setUpBeforeClass(): void
+    {
+        self::$schemaFile = dirname(__FILE__, 6) . '/resources/schemas/oasis-sstc-saml-schema-protocol-1.1.xsd';
+
+        self::$testedClass = StatusCode::class;
+
+        self::$xmlRepresentation = DOMDocumentFactory::fromFile(
+            dirname(__FILE__, 5) . '/resources/xml/samlp_StatusCode.xml',
+        );
+    }
+
+
+    /**
+     */
+    public function testMarshalling(): void
+    {
+
+        $statusCode = new StatusCode(
+            C::STATUS_RESPONDER,
+            [
+                new StatusCode(C::STATUS_REQUEST_DENIED),
+            ],
+        );
+
+        $this->assertEquals(
+            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
+            strval($statusCode),
+        );
+    }
+}