Short answers, pulled from the story.
Thomas Tallis (c. 1505-1585) was an English composer of High Renaissance sacred vocal music who served as organist and composer in the Chapel Royal under Henry VIII, Edward VI, Mary I, and Elizabeth I. He is considered one of England's greatest composers, known for his versatility across radically different religious and stylistic demands across more than four decades of royal service.
Spem in alium is a motet scored for eight five-voice choirs, making forty voices in total. It is thought to have been commissioned by the Earl of Arundel and draws its text from the apocryphal Book of Judith. The motet contains deliberate numerology: its forty voices correspond to the forty days of Christ in the Desert, and its length of 69 'longs' spells out T-A-L-L-I-S in Latin letter values.
In 1575, Elizabeth I granted Tallis and Byrd a 21-year monopoly over polyphonic music printing, one of the first arrangements of its kind in England. It gave them exclusive rights to print music in any language and sole control of the paper used in music printing. The only publication issued under the monopoly while Tallis was alive was the 1575 Cantiones quae ab argumento sacrae vocantur, which did not sell well.
Tallis's Canon is a psalm tune that originated as one of nine chant settings Tallis wrote for four voices for Archbishop Matthew Parker's Psalter, published in 1567. A version of it published by Thomas Ravenscroft became the tune for Thomas Ken's hymn "All praise to thee, my God, this night."
Ralph Vaughan Williams based his 1910 Fantasia on a Theme by Thomas Tallis on the "Third Mode Melody," one of nine psalm tunes Tallis composed for Archbishop Matthew Parker's Psalter of 1567.
Tallis was buried in the chancel of St Alfege Church in Greenwich. A brass memorial plate was placed there after the death of his wife Joan, but it was lost when the church was rebuilt in the 1710s; his remains may have been disturbed by labourers during that reconstruction. His epitaph was preserved by John Strype in his 1720 edition of John Stow's Survey of London.