History of England
With Henry VII's accession to the throne in 1485, the Wars of the Roses came to an end, and Tudors would continue to rule England for 118 years. Traditionally, the Battle of Bosworth Field is considered to mark the end of the Middle Ages in England, although Henry did not introduce any new concept of monarchy, and for most of his reign his hold on power was tenuous. He claimed the throne by conquest and God's judgement in battle. Parliament quickly recognized him as king, but the Yorkists were far from defeated. Nonetheless, he married Edward IV's eldest daughter Elizabeth in January 1486, thereby uniting the houses of York and Lancaster.
Elizabethan government
Elizabeth is considered by many to be one of England's best monarchs. She was wise and just, chose good advisers and wasn't dominated by them, dealt with the stubbornly resistant Parliaments without being tyrannous, and was skilled at compromising in both religious and political matters. She ruled for 45 years and was the sixth and last of the Tudor dynasty.
Sir William Cecil (named Lord Burghley in 1571) was her chief adviser and supervised the whole administration. He was also Secretary of State from 1558 to 1572 and Lord Treasurer from 1572 to his death in 1598. Sir Francis Walsingham was famous for uncovering many Catholic plots against Elizabeth; he filled in as Secretary of State from 1572 to his death in 1590. Sir Robert Cecil, second son of Sir William Cecil, was Secretary of State in 1596 and master of Court of Wards after a clash with Robert Devereux, Earl of Essex. He then became dominant in the government.