He came to Brazil, where in Rio de Janeiro he was hired and accepted the service of Prince Regent Peter on July 3, 1822. He was given the rank of brigadier general, because of the shortage of officers in the newly organized army.
He organized the Army called Peacemaker, name probably suggested by the Minister of Foreign Affairs and José Bonifácio de Andrada. He followed with his troops for the Bahia, the squadron commanded by Division Chief Rodrigo de Lamare, consisting of a Frigate, two Corvette and two brigs, with a mission to face the Portuguese general Inácio Luís Madeira de Melo. He entrenched his forces in defiance of the Regent. He beat the Portuguese in the Battle of Pirajá.
Peter Labatut received the title of Marechal-de-campo. He left active service in 1842 and died in the ancient streets of Salvador Barris. The town renamed the street Labatut General.