Cungagnaq, presumably a native of Kodiak Island (Aleutian Islands). He is said to have received the Christian name of Peter when he was baptized into the Orthodox faith by the monks of St. Herman's missionaries operating in the north. In 1815 a group of Aleut seal and otter hunters, including Peter, was captured by Spanish sailors, who took them to San Francisco for interrogation. With threats of torture, the Roman Catholic priests in California attempted to force the Aleuts to deny their Orthodox faith and to convert to Roman Catholicism.

When the Aleuts refused, the priest had a toe severed from each of Peter's feet. Peter still refused to renounce his faith and the Spanish priest ordered a group of California Indians to cut off each finger of Peter's hands, one joint at a time, finally removing both his hands. They eventually disemboweled him, crowning his life with martyrdom. They were about to torture the next Aleut when orders were received to release them.

Upon receiving the report of Peter's death, St. Herman back on Kodiak Island was moved to cry out, "Holy new-martyr Peter, pray to God for us!" Peter the Aleut was formally declared a Saint as the "Martyr of San Francisco" in 1980. His feast day is commemorated in the Orthodox faith on September 24.