The Wars of the Roses, known at the time and in following centuries as the Civil Wars, were a series of civil wars fought over control of the English throne from 1455 to 1487. The wars were fought between supporters of the House of Lancaster and House of York, two rival cadet branches of the royal House of Plantagenet. The conflict resulted in the end of Lancaster's male line in 1471, enabling the Tudor family to inherit their claim to the throne through the female line. Conflict was largely brought to an end upon the union of the two houses through marriage, creating the Tudor dynasty that would subsequently rule England.

The House of Lancaster was a cadet branch of the royal House of Plantagenet. The first house was created when King Henry III of England created the Earldom of Lancaster—from which the house was named—for his second son Edmund Crouchback in 1267. Edmund had already been created Earl of Leicester in 1265 and was granted the lands and privileges of Simon de Montfort, 6th Earl of Leicester, after de Montfort's death and attainder at the end of the Second Barons' War. When Edmund's son Thomas, 2nd Earl of Lancaster, inherited his father-in-law's estates and title of Earl of Lincoln he became at a stroke the most powerful nobleman in England, with lands throughout the kingdom and the ability to raise vast private armies to wield power at national and local levels. This brought him—and Henry, his younger brother—into conflict with their cousin King Edward II, leading to Thomas's execution. Henry inherited Thomas's titles and he and his son, who was also called Henry, gave loyal service to Edward's son King Edward III.