Short answers, pulled from the story.
William Cecil 1st Baron Burghley was born on the 13th of September 1520 in Bourne, Lincolnshire. He was born into a family that had climbed the social ladder from the Welsh Marches to the heart of English politics.
William Cecil 1st Baron Burghley held the offices of Secretary of State and Lord High Treasurer from 1572. He served as the most important minister of the reign from 1558 until his death.
William Cecil 1st Baron Burghley died at his London residence, Cecil House, on the 4th of August 1598. He was buried in St Martin's Church, Stamford.
William Cecil 1st Baron Burghley supported the execution of Mary Queen of Scots in 1587 because he argued she had become a rallying cause for Catholics. He believed she played into the hands of Spain and the Pope who had excommunicated Elizabeth in 1570.
William Cecil 1st Baron Burghley built Burghley House near Stamford between 1555 and 1587. He also constructed Theobalds House in Cheshunt which accommodated the Queen on her eight visits between 1572 and 1596.