The street is named after Sir George Downing, who was born in Ireland and brought up in New England, and was one of the earliest graduates of Harvard. He came to England during the Civil War and by 1650 had become Cromwell’s intelligence chief, known as the Scoutmaster General. In 1657 he became British Ambassador to The Hague. The next year Cromwell died and Downing deftly offered his services to Charles II. In 1682, Downing secured the lease on a piece of land close to Westminster and set about building the street that bears his name. Samuel Pepys described him as a “perfidious rogue”.
In the Middle Ages, the ground underneath Downing Street and the Houses of Parliament was known as Thorney Island. It lay between two branches of the River Tyburn (which today flows directly under the Treasury in Parliament Street). The earliest known building on the site of Downing Street was the Axe brewery owned by the Abbey of Abingdon. It had fallen into disuse by the early 16th century.