William (French Guillaume) Repin was born on August 26, 1709 at Thouars. Ordained priest in 1734, Guillaume served as parish priest at Martigné-Briand in the Vendée region for the 60 years (1734–1794).
During the Vendée Wars (1793–1796) — the Catholic-royalist Vendéen peasant revolt against the revolutionary government — the city of Angers became the center of the systematic revolutionary trials of the Vendéen Catholic clergy, religious, and laity.
Between January 1793 and April 1794, 99 Catholic clergy, religious, and lay-Catholic Vendéens were guillotined at Angers — the Angers Martyrs.
Guillaume Repin — arrested in December 1793 at the age of 84 — was guillotined at Angers on January 2, 1794 as the eldest of the Angers Martyrs.
Among the 99 Angers Martyrs include: 12 priests (including Guillaume Repin); 4 female religious (the Sisters of Charity Marie-Anne Vaillot and Odile Baumgarten, guillotined October 1, 1794); 83 lay-Catholic Vendéens (majority women, systematically guillotined for Catholic-royalist convictions).
Beatified February 19, 1984 by Pope St. John Paul II — one of the most extensive beatifications of the French Revolution martyr tradition.