Richard II 1377-99 -- murdered. Richard is the eldest son of the eldest son of Edward III who has descended in a straight line of eldest sons since William the Conquerer (1066).

Henry IV (Lancaster) 1399-1413 -- murdered his cousin, Richard II

Henry V 1413-22

Henry VI 1422-61 -- murdered by York cousins

Edward IV (York) 1461-83 His two sons, heirs, are murdered by his brother.

Richard III (York) 1483-85 Brother of Edward IV; Richard dies in battle.

Henry VII (Lancaster) 1485-1509 Henry is son of Margaret Beaufort and Edmund Tudor; Edmund Tudor is the son of Owen Tudor and Katherine (widow of Henry V), so Henry is related through his grandmother to the Lancasters. His Beaufort mother is descended from the second family of John of Gaunt, Duke of Lancaster.

Henry VIII (Lancaster/York) 1509-47 Henry VII marries a York cousin, the daughter of Edward IV, and the sister of the two sons of Edward IV who were murdered by their York uncle, Richard III. Henry VIII, aware of the precariousness of this cease-fire between the two families, Yorks and Lancasters, is determined to have a male heir to save the country more blood-shed and civil war.

To this purpose, he divorces his wife Katherine of Aragon because she has only produced a daughter. When the Pope does not sanction the divorce (grant an annulment), Henry splits England from the Catholic Church. Protestantism is now the official religion of England.

Henry marries Anne Boleyn who also, disappointingly, has a daughter, Elizabeth; Henry executes Anne.

Henry marries Jane Seymour who produces male heir, Edward VI.

Edward VI 1547-53 Dies as a child.

Mary 1553-58 Katherine of Aragon's daughter, Catholic, known as 'Bloody Mary' for the religious wars between Catholics and Protestants. Mary wanted to reinstate Catholicism.

Elizabeth 1558-1603 Daughter of Anne Boleyn, Protestant; dies without heir.

James I 1603-25 Heir to throne of Scotland; his mother, Mary Queen of Scots, cousin to Elizabeth, was executed by Elizabeth.