diff --git a/src/main/java/envoy/data/Contact.java b/src/main/java/envoy/data/Contact.java
index 96b703e..e7a22ed 100644
--- a/src/main/java/envoy/data/Contact.java
+++ b/src/main/java/envoy/data/Contact.java
@@ -36,7 +36,7 @@ public abstract class Contact implements Serializable {
 	 * @return the ID of this {@link Contact}
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public long getId() { return id; }
+	public long getID() { return id; }
 
 	/**
 	 * @return the name of this {@link Contact}
diff --git a/src/main/java/envoy/data/Group.java b/src/main/java/envoy/data/Group.java
index 4c662cc..44f91d4 100644
--- a/src/main/java/envoy/data/Group.java
+++ b/src/main/java/envoy/data/Group.java
@@ -59,7 +59,7 @@ public class Group extends Contact {
 	@Override
 	public String toString() {
 		var joiner = new StringJoiner(",", "Group[id=", "]");
-		joiner.add("id=" + getId());
+		joiner.add("id=" + getID());
 		joiner.add("name=" + getName());
 		joiner.add("memberIDs=" + getMemberIDs());
 		return joiner.toString();
diff --git a/src/main/java/envoy/data/User.java b/src/main/java/envoy/data/User.java
index be3881e..d282e29 100644
--- a/src/main/java/envoy/data/User.java
+++ b/src/main/java/envoy/data/User.java
@@ -73,7 +73,7 @@ public class User extends Contact {
 	}
 
 	@Override
-	public String toString() { return String.format("User[id=%d,name=%s,status=%s]", getId(), getName(), status); }
+	public String toString() { return String.format("User[id=%d,name=%s,status=%s]", getID(), getName(), status); }
 
 	/**
 	 * @return the current status of this user
diff --git a/src/main/java/envoy/event/GroupResizeEvent.java b/src/main/java/envoy/event/GroupResizeEvent.java
new file mode 100644
index 0000000..1b6d153
--- /dev/null
+++ b/src/main/java/envoy/event/GroupResizeEvent.java
@@ -0,0 +1,86 @@
+package envoy.event;
+
+import envoy.data.Contact;
+import envoy.data.Group;
+import envoy.data.User;
+
+/**
+ * Project: <strong>envoy-common</strong><br>
+ * File: <strong>GroupResizeEvent.java</strong><br>
+ * Created: <strong>25 Mar 2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Common v0.1-beta
+ */
+public class GroupResizeEvent extends Event<Long> {
+
+	private final long		groupID;
+	private OperationType	operationType;
+
+	private static final long serialVersionUID = 0L;
+
+	/**
+	 * Project: <strong>envoy-common</strong><br>
+	 * File: <strong>GroupResizeEvent.java</strong><br>
+	 * Created: <strong>25 Mar 2020</strong><br>
+	 *
+	 * @author Leon Hofmeister
+	 * @since Envoy Common v0.1-beta
+	 */
+	public enum OperationType {
+		/**
+		 *
+		 */
+		ADD,
+		/**
+		 *
+		 */
+		REMOVE
+	}
+
+	/**
+	 * Initializes a {@link GroupResizeEvent} through a Contact where the name has
+	 * already been set.
+	 *
+	 * @param user          the {@link User} who wants to join or leave a group
+	 * @param group         the {@link Group} he wants to join or leave
+	 * @param operationType whether the user should be removed from this group. If
+	 *                      false,
+	 *                      this user will be added
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public GroupResizeEvent(User user, Group group, OperationType operationType) {
+		super(user.getID());
+		if (group.getMemberIDs().contains(user.getID())) {
+			if (operationType.equals(OperationType.ADD)) throw new IllegalStateException(
+					"Cannot add " + user + " to group " + group.getID() + " because he is already a member of this group");
+		} else if (operationType.equals(OperationType.REMOVE))
+			throw new IllegalStateException("Cannot remove " + user + " from group " + group.getID() + " because he is no part of this group");
+		groupID				= group.getID();
+		this.operationType	= operationType;
+	}
+
+	/**
+	 * @return the ID of the {@link Contact} this event is related to
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public long getGroupId() { return groupID; }
+
+	/**
+	 * @return the operationType
+	 * @since Envoy Common v0.1-beta
+	 */
+	public OperationType getOperationType() { return operationType; }
+
+	/**
+	 * @param operationType the operationType to set
+	 * @since Envoy Common v0.1-beta
+	 */
+	public void setOperationType(OperationType operationType) { this.operationType = operationType; }
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String toString() { return String.format("GroupResizeEvent[userid=%d,groupid=%d,operationType=%b]", get(), groupID, operationType); }
+}
\ No newline at end of file
diff --git a/src/main/java/envoy/event/NameChangeEvent.java b/src/main/java/envoy/event/NameChangeEvent.java
new file mode 100644
index 0000000..4cfa640
--- /dev/null
+++ b/src/main/java/envoy/event/NameChangeEvent.java
@@ -0,0 +1,52 @@
+package envoy.event;
+
+import envoy.data.Contact;
+
+/**
+ * This event informs<br>
+ * a) the server of the name change of a user or a group.
+ * b) another user of this users name change.
+ *
+ * Project: <strong>envoy-common</strong><br>
+ * File: <strong>NameChangeEvent.java</strong><br>
+ * Created: <strong>25 Mar 2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Common v0.1-beta
+ */
+public class NameChangeEvent extends Event<String> {
+
+	private static final long	serialVersionUID	= 0L;
+	private final long			id;
+
+	/**
+	 * Creates a new {@link NameChangeEvent} for a user or a group.
+	 *
+	 * @param contactID the id of the {@link Contact} who wishes to change his name
+	 * @param newName   the new name of this contact
+	 * @since Envoy Common v0.1-beta
+	 */
+	public NameChangeEvent(long contactID, String newName) {
+		super(newName);
+		id = contactID;
+	}
+
+	/**
+	 * Initializes a {@link NameChangeEvent} through a Contact where the name has
+	 * already been set.
+	 *
+	 * @param contact the contact whose name was updated
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public NameChangeEvent(Contact contact) { this(contact.getID(), contact.getName()); }
+
+	/**
+	 * @return the ID of the {@link Contact} this event is related to
+	 * @since Envoy Common v0.2-alpha
+	 */
+	public long getId() { return id; }
+
+	@Override
+	public String toString() { return String.format("NameChangeEvent[id=%d,name=%s]", id, value); }
+
+}
diff --git a/src/main/java/envoy/event/UserStatusChangeEvent.java b/src/main/java/envoy/event/UserStatusChangeEvent.java
index 8349653..8ab198c 100644
--- a/src/main/java/envoy/event/UserStatusChangeEvent.java
+++ b/src/main/java/envoy/event/UserStatusChangeEvent.java
@@ -36,7 +36,7 @@ public class UserStatusChangeEvent extends Event<UserStatus> {
 	 * @param user the User from which to build the event
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public UserStatusChangeEvent(User user) { this(user.getId(), user.getStatus()); }
+	public UserStatusChangeEvent(User user) { this(user.getID(), user.getStatus()); }
 
 	/**
 	 * @return the ID of the {@link User} this event is related to