While in the United States, he was invited to join South American patriots in the
Army of the Andes. However, he did not manage to arrive in time for the army's crossing of the Andes into Chile and the decisive
battle of Chacabuco. When he arrived he soon begun to participate in engagement with the royalist; first in the siege of
Talcahuano (1817) and later on in the decisive patriot victory at the
Battle of Maipú (1818). In 1819 he joined the newly formed
Chilean Navy under the command of
Lord Cochrane. In February 1820 he led an amphibious assault on the heavily
fortified Corral Bay leading to the
capture of Valdivia. He stayed in Valdivia to chase remaining royalists while Cochrane sailed further south to
Chiloé Island. Beauchef then left Valdivia to expel the royalists from
Osorno. The royalist forces of Valdivia had fled to Osorno and then gathered at
Carelmapu fort where they received orders from
Antonio de Quintanilla to confront Beauchef. In the
Battle of El Toro (1820) Beauchef succeeded in defeating the royalist expedition. In 1823 he was sent in charge of a reinforcement to
José de San Martín's army in Peru. There he served as governor of
Lima for a short time. Back in Chile he participated in the 1824 expedition to Chiloé Island where he was defeated in the
Battle of Mocopulli. Chiloé would only be incorporated into Chile after
Ramón Freire's 1826 expedition. == Later years ==