Thomas, Earl of Lancaster (c. 1278–1322), was a prominent English nobleman and a key figure during the early 14th century. He was the son of Henry, Earl of Lancaster and Maud Chaworth, and he played a significant role in the political landscape of England, particularly during the reign of King Edward II. Thomas was known for his opposition to the king's favorites and his involvement in the Barons' Wars. As a member of the Plantagenet family, Thomas held considerable power and land. His rivalry with Edward II escalated, leading to his eventual rebellion against the king. In 1322, Thomas was captured and executed, marking a significant moment in the ongoing conflict between the monarchy and the nobility in England.