The War of the Roses (1455–1485) was a series of civil wars fought over the throne of England between adherents of the House of Lancaster and the House of York. Both houses were branches of the Plantagenet royal house, tracing descent from King Edward III. The conflict resulted from social and financial troubles that followed the Hundred Years' War against France, combined with the mental infirmity and weak rule of Henry VI, which revived interest in the alternative claim to the throne of Richard, Duke of York.
The final victory went to a Lancastrian claimant, Henry Tudor, who defeated the last Yorkist king, Richard III, at the Battle of Bosworth Field. After assuming the throne as Henry VII, Henry Tudor married Elizabeth of York, the daughter of Edward IV, thereby uniting the two houses. The House of Tudor ruled England, Wales, and Ireland from 1485 until 1603.
The tensions that begat the War of the Roses were quite palpable in 1452, which prompted Edward Radcliffe and his family to leave England and settle in the newly discovered Atlantis.
By and large, the War remained in England. When Radcliffe returned to England, he'd either remain neutral or declare for whichever side appeared to be winning at the moment. For his part, Radcliffe didn't care which side won. New Hastings grew as people fled the war. Soon, a second English colony, Freetown, was established south. The two towns had very little to do with each other, as the citizens of Freetown were more nationalistic.
The War finally had a definitive impact on Atlantis when in 1470, when King Edward IV, having finally captured the throne, banished long-time military and political supporter, the Earl of Warwick to Freetown. Warwick instead arrived in New Hastings, leading to a brief but bloody period of conflict culminating in the Battle of the Strand.