Welsh monarchs refer to the rulers of Wales before its annexation by England. The most notable among them was Llywelyn the Great, who united various Welsh principalities in the 13th century. His grandson, Llywelyn ap Gruffudd, also known as Llywelyn the Last, was the last sovereign Prince of Wales before the English conquest. After the conquest, Wales was incorporated into the Kingdom of England, and the title of Prince of Wales was created for the heir apparent of the English crown. Today, the title is held by the eldest son of the reigning monarch, currently Prince William.