William Byrd was an English composer of the Renaissance. He wrote in many of the forms current in England at the time, including various types of sacred and secular polyphony, keyboard (the so-called Virginalist school) and consort music. Our knowledge of Byrd's biography has expanded in recent years, thanks largely to the research of John Harley (Harley, 1997). Following the discovery of a document dated 2 October 1598 in which Byrd's age is given as "58 years or there abouts," it now appears that he was born in 1540. The older dating 1542–3 is derived from Byrd's will (endorsed on 22 November 1622) which describes him as 'in the 80th year of my age'. It now becomes clear that it must have been drafted about three years earlier than the date of endorsement.