Born the son of Admiral Hugh Pigot, Pigot was commissioned as a cornet in 1769. He served in the Netherlands in 1793 and, following the Siege of Malta, accepted the surrender of Valletta from the French forces under General Claude-Henri Belgrand de Vaubois in September 1800. He went on to be Civil Commissioner of Malta in February 1801. As civil commissioner, he accepted the demolition of the majority of the fortifications of Valletta, but this act was never done and the city walls survive largely intact to this day.