House of York
The House of York was descended from Edmund Duke of York, the third son of Edward III.
When Henry VI suffered a bout of madness in 1454, his cousin Richard, Duke of York ruled as Protector. When Henry recovered, Richard did not want to give up power and the Cousin's War began.
Eventually Richard, Henry VI and his son Edward of Lancaster were all killed and Richard's son Edward ruled as Edward IV.
When Edward IV his son Edward became king but before long he and his younger brother Richard went missing at the Tower of London and their uncle declared himself Richard III.
Lancastarian armies rose up again and at the Battle of Bosworth Field the Lancastrian heir, Henry Tudor, defeated Richard and the Wars of the Roses came to an end.