Lieutenant Liam Docherty appears in Sharpe's Siege. He is the first mate aboard the American Privateer, Thuella.

Born in Ireland at Cashelnavean, "on the road to Ballybofey," in County Donegal, where his family farmed until their land was taken by the English, and his father hanged as a rebel. His uncle was the smith in Meencrumlin, a man whom Patrick Harper knew, and who used to tinker his mother's pots.

After Docherty father's death, his mother took the boy to America, but she never let him forget. By 1812, he was glad for the chance to fight the English.

Captured after the British assualt on the fort at Teste de Buch, France, he and his captain, Cornelius Killick, were bound and beaten by Royal Navy Captain, Horace Bampfylde, who burned their Letter of Marque and the citizenship papers of their crew. When Sharpe offered Docherty and his captain an escape from the rope Horace Bampfyled had planned for them, he began to question Sharpe's truthfulness, only to be slapped down harshly in Gaelic by Harper, no one else knew what was said, but he then answered Sharpe with "sudden, unnatural humility," and gave his parole.