Ursula Vaughan Williams was born in Valletta, Malta, where her father, Major Robert Lock, was aide de camp to the General officer commanding, Arthur Pole Penton.

The musicologist Oliver Neighbour writes that after moving from Brussels "she passed the next four years, horribly bored and reacting sharply against the social round in which she was expected to take part".

[3] Neighbour records that she occupied herself with reading, writing poetry, archaeology and amateur dramatics, "and finally escaped to London" in 1932–33 to study at the Old Vic theatre.

[3] While a student there she was able to attend some performances free of charge, and one evening she saw Job, a ballet by Ninette de Valois with a score by Ralph Vaughan Williams.

[5] Between then and the Second World War she wrote prose and verse and contributed to the BBC and the Times Literary Supplement, while living the peripatetic life of an army wife.

[8] Ursula became the composer's muse, helper and London companion, and later helped him care for his ailing wife, Adeline, who had arthritis so severe as to confine her to the house in Dorking where she and her husband had lived since 1929.

The composer's concern for his first wife never faltered, according to Ursula, who admitted in the 1980s that she had been jealous of Adeline, whose place in Vaughan Williams's life and affections was unchallengeable.

With her support he resumed the composition he had been forced to set aside during his first wife's illness; Ursula wrote the libretto for two of his last choral works, including the cantata for Christmas Hodie.