Born at the family home at 18 Poultney Street in Bath, Labalmondière was descended from an aristocratic French family who had established sugarcane plantations in the West Indies. He was educated at Eton College and the Royal Military College, Sandhurst, where he passed out at the head of the list with exceptional honours, and was commissioned an ensign into the 83rd (County of Dublin) Regiment of Foot (later the Royal Irish Rifles). He served in the Canadas, 1837–1838, carried dispatches during Mackenzie's Rebellion and Papineau's Rebellion, and was promoted lieutenant. He was promoted captain in 1844. In 1846–1849, he served in Ireland during the Great Famine, as temporary inspector with special duties under the Poor Law Commissioners. Following closure of the local relief committees in 1847, public testimonials of his endeavours were sent by committees in Castlegregory, Castleisland, Ventry, Tralee and Ballincuslane.