Sir Thomas Sackville, 1st Earl of Dorset (1536 – April 19, 1608) was an English statesman and poet, son of Richard Sackville. He was a Member of Parliament and Lord High Treasurer. His houses, Knole House, at Knole in Kent, and Michelham Priory are celebrated.
He was author, with Thomas Norton, of the play Gorboduc (1561), the first English drama to be written in blank verse and deals with the consequences of political rivalry. He and also contributed to 1563 edition of Mirror for Magistrates, with the poem Complaint of Henry, Duke of Buckingham. Sackville's first important work was the poem Induction which decibies the poet's journey to the infernal regions, where he encounter figures representing forms of suffering and terror. The poem is noted for the power of its allegory and for its sobre stateliness of tone.
He was created Baron Buckhurst, of Buckhurst in the County of Sussex, in 1567, and Earl of Dorset in 1604. He succeeded William Cecil, Lord Burghley as Lord Treasurer for life in 1599, and was a capable, if uninspired, financial manager. In 1604 Sackville bought Groombridge Place in Kent. He died in 1608.
Sackville acquired a large fortune through his real estate dealings in many counties, as well as his investments in the iron foundry business. His personal financial dealings earned him, perhaps unflatteringly, the sobriquet of "Sir John Fillsack."
Queen Elizabeth I acquired Bexhill Manor in 1590 and granted it to Thomas. Thomas was also the last Sackville to be Lord of the Manor of Bergholt Sackville (named after the Sackville family) and Mount Bures in Essex when he sold them in 1578 to Mrs Alice Dister. Both estates had been in the family for 459 years.
He married Cicely Baker and had 7 children.