Remember - when the Romans left Britain there were many different 'kings' and small kingdoms under subsequent invasions of Angles, Jutes and Saxons. Eventually there was once again a single ruler - the first for our purposes being Alfred the Great in 871.

1066-1087: William the Conqueror
1087-1100: William II
1100-1135: Henry I
1135-1154: Stephen

The Plantagenet Kings succeeded the Normans.
1154-89: Henry II
1189-99: Richard I (Lionheart)
1199-1216: John
1216-1272: Henry III
1272-1307: Edward I
1307-27: Edward II
1327-77: Edward III

Lancasters and Yorks - entering the time of the Wars of the Roses
1377-99: Richard II
1399-1413: Henry IV
1413-22: Henry V
1422-61/70-71: Henry VI
1461-70/71-83: Edward IV
1483: Edward V
1483-5: Richard III

1485-1509: Henry VII
1509-47: Henry VIII
1547-53: Edward VI
1553-8: Mary I
1558-1603: Elizabeth I

Early Modern Britain BEGINS!
1603-25: James I
1625-49: Charles I
1649-60: Commonwealth (Cromwell)
1660-85: Charles II
1685-8: James II
1689-1702: William III & Mary II
1702-14: Anne

Industrialisation kicks off!
1714-27: George I
1727-60: George II
1760-1820: George III
1820-30: George IV
1830-37: William IV

1837-1901: Victoria

1901-10: Edward VII
1910-36: George V
1936: Edward VIII
1936-52: George VI
1952- : Elizabeth II