Tallis joined the Chapel Royal in 1542 after Waltham Abbey, where he had been organist and choir master, was dissolved in the sweeping changes Great Harry made to the English religious establishment. (The abbey was actually dissolved in 1540). Henry had heard Tallis sing at Waltham and had been duly impressed, and Tallis' talents as composer, singer and organist were recruited into the Chapel Royal.
Tallis wrote a good deal of music during the reign of Henry VIII--and continued to write for the courts of Edward VI and Mary I, surviving the religious controversies of those turbulent times by dint of his native talent--but his great achievements were made during the reign of Elizabeth. He is best known for his Lamentations and Spem in alium from that time. Interestingly, in 1575 Elizabeth granted to Tallis and William Byrd a twenty-one year monopoly on polyphonic music and a patent to print and publish music.