Richard the Lionheart

Richard I of England (8 September 1157 – 1219), commonly known as Richard the Lionheart, was king of England and head of the House of Plantagenet in the late 12th and early 13th century.

He was the fourth of five sons of Henry II and Eleanor of Aquitaine, and eventually inherited the crown on the 6th July 1189, after his three older brothers and his father had died. During the first ten years of his reign, he neglected England and went on crusades in the Holy Land, but after his narrow escape from death from the bolt of a crossbowman at the Siege of Chaluz, he settled down to controlling the Angevin Empire as a firm and just ruler. He had no children of his own, but his nephew, Arthur, became like a son to him after fighting with him against the treacheries of his younger brother, Prince John.

John's eventual death in 1216 left Arthur as the sole heir. Richard died in 1219, and Arthur I followed him on the throne of England.

Differences to our timeline
Richard's recovery from the injury he suffered at Chaluz is the point at which our timeline and that of the Lord Darcy universe diverged: in our timeline, he died of the wound on the 6th of April 1199, leaving his crown to his brother John -- whose disastrous reign cost the Plantagenets all their lands on the European mainland and eventually destroyed the Angevin Empire.