Thomas Tallis (c. 1505-1585) was an English composer. He was appointed organist of Waltham Abbey about 1536, until the abbey was dissolved in 1540. He became a gentleman of the Chapel Royal in 1542, composing and performing for Henry VIII, Edward VI, Queen Mary, and Queen Elizabeth.
He remained an avowed Catholic his entire life, and his music composition for the Catholic Church continued unimpeded when the Church of England became the law upon the coronation of Elizabeth in 1559.
In the Chapel Royal he held the honorary title of organist, which he eventually shared with his student William Byrd. In 1575 the two composers obtained a license from Queen Elizabeth to print music and music-paper. He was also given lands valued at 30 pounds sterling per year by Elizabeth, as well as various tithes. He was buried in St Alfege's Church, Greenwich, London.
His prolific musical output includes many Masses, motets, as well as music for the Anglican church. One of his best known compositions is Spem In Alium, a magnificent motet for 40 voices.
One of nine tunes Tallis composed in 1567 as part of a psalter inspired the composition of Fantasia on a Theme by Thomas Tallis by Ralph Vaughan Williams in 1910.