De Anda y Salazar was an Oidor of the Royal Audience of Manila, who was appointed as Lieutenant Governor of the city by the Governor-General of the Philippines and the Audiencia itself during the British occupation of Manila. He departed Manila on the night of October 5, 1762, during the Battle of Manila (1762), and established Spanish a provisional colonial government and army in Bulacan. The acting governor of Manila, Archbishop Manuel Rojo, was captured by the British and surrendered the Philippines, but this act was rejected as illegal by Anda.