Joined the Carthusians on 18 December 1769 at the monastery of Fontenay, France. Priest. Served as vicar of his house until June 1791 when the monastery was suppressed by the civil authorities of the French Revolution. Arrested on 19 April 1793 for refusing to take the oath that would have switched his allegience from the Vatican to the civil authorities of the Revolution. Imprisoned on a ship in the harbor of Rochefort, France and left to die. There he ministered to other prisoners, hearing confessions, doing what little he could for the sick. One of the Martyrs of the Hulks of Rochefort.
- 10 August 1794 aboard the prison ship Washington, in Rochefort, Charente-Maritime, France of a fever
- buried on the island of Aix, France
- “Blessed Lazare Tiersot“. CatholicSaints.Info. 30 July 2016. Web. 6 December 2016. <>