Henry Stewart (or Stuart, which was the style adopted by his father, and thence perpetuated as the House of Stuart), 1st Duke of Albany (7 December, 1545 – 9 or 10 February, 1567), commonly known as Lord Darnley, King Consort of Scotland, was the first-cousin and second husband of Mary, Queen of Scots, and the father of her son James VI of Scotland, who became James I of England.

Henry Stuart, 1st Duke of Albany

Darnley was born on December 7, 1545, at Temple Newsham in Yorkshire, the son of Matthew Stewart, 4th Earl of Lennox, and his wife Margaret Douglas. He was related to his future wife in at least three ways: They shared a grandmother in Margaret Tudor, putting both Mary and Darnley high in the line of succession for the English throne. He was descended from James II of Scotland through his second son, and thus also in line for the throne of Scotland. Darnley's family surname was due to a much more ancient connection to his male-line ancestor, Alexander Stewart, 4th High Steward of Scotland. By the time of his marriage to Mary on July 29, 1565, he was second in line to the Scottish throne after Mary herself. On their marriage, which took place in the chapel of Palace of Holyroodhouse in Edinburgh, Darnley was given the title of "King of Scotland," but he was a king consort only, with no royal powers.

The marriage was a disaster. Darnley was younger than Mary and not particularly mature for a nineteen-year-old. He was unpopular with the other nobles and had a mean and violent streak. Within a short time, Mary became pregnant, but Darnley grew more and more demanding. His jealousy of Mary's private secretary, David Rizzio, culminated in the bloody murder of the latter by Darnley and a group of his friends, in the presence of the queen herself at Holyrood Palace. Following the birth of her son, the future James VI of Scotland, the succession was more secure, and Mary turned to a friend, James Hepburn, 4th Earl of Bothwell, for help. On February 10, 1567, Darnley's body was discovered in the gardens of the Provost's House, Edinburgh, where he had been staying. An explosion had occurred that night at the house, but the evidence pointed to Darnley's having escaped that attempted assassination only to be murdered when he got outside. Suspicion fell on Bothwell and on Mary herself, who shortly married Bothwell, and Darnley's death was a key event in the downward spiral that led to her loss of the Scottish crown.