Short answers, pulled from the story.
The House of Plantagenet was a royal house that originated in the French county of Anjou and held the English throne from 1154 to 1485. Modern historians use the name to identify four distinct royal houses: the Angevins, the main Plantagenet line after the loss of Anjou, and the cadet branches of Lancaster and York.
The House of Plantagenet held the English throne from 1154, with the accession of Henry II, until 1485, when Richard III died in battle. The reign of the Plantagenets and the English Middle Ages both ended at the Battle of Bosworth Field in 1485.
The name Plantagenet came from Plantegenest, a 12th-century nickname for Geoffrey, Count of Anjou and Duke of Normandy. One popular theory traces it to the blossom of the common broom, a bright yellow flowering plant called genista in medieval Latin. Richard of York adopted Plantagenet as his family name in the 15th century.
Historians disagree on the first Plantagenet king. Those who do not distinguish between Angevins and Plantagenets count Henry II, who acceded in 1154, while others consider John's son Henry III to be the first Plantagenet monarch after the loss of Anjou.
The Plantagenet line of kings ended in 1485 when Richard III was killed at the Battle of Bosworth Field and Henry VII took the throne to found the Tudor dynasty. The legitimate male line of the house went extinct with the execution of Edward, Earl of Warwick, in 1499.
The Wars of the Roses arose from the rivalry between the Plantagenets' two cadet branches, the House of York and the House of Lancaster, in a decades-long fight for the English succession fought between 1455 and 1487. It ended when Henry VII, a Lancastrian, married Elizabeth of York and began the Tudor dynasty.