The House of Plantagenet was a royal dynasty that ruled England from the 12th to the 15th centuries. It began with Henry II in 1154 and included notable monarchs like Richard the Lionheart and King John, who signed the Magna Carta in 1215. The dynasty is known for its significant influence on English law and governance. The Plantagenets were involved in various conflicts, including the Hundred Years' War against France. The house eventually split into two branches: the Lancasters and the Yorks, leading to the Wars of the Roses. The dynasty ended with Richard III, who was defeated in 1485.