He was actually a Swiss national, born in Geneva in 1788. He served in the French army during the Peninsular war and was seriously injured. Back in Geneva, he had an affair with Germaine de Staël, who, exiled from Paris by Napoleon, lived in her castle at near-by Coppet. The lady bore a son on 7 April 1812, whom his father legitimated as Louis-Alphonse Rocca. They separated when Madame de Staël started on a European tour, to reach London through Vienna, Moscow, St.Petersburg and Stockholm. Later they married and moved together to Paris after Waterloo and Napoleon's second abdication. Germaine de Staël suffered a seizure on 5 January 1817, that left her paralysed, and died on 14 July 1817, soon followed by her husband, who died in Hyères (Var) on 31 January 1818.
He left two descriptions of the military events in which he was involved: "Mémoire sur la guerre des Français en Espagne" and "La campagne de Walcheren et d'Anvers" (a failed landing by the British in Belgium)". His portrait as Hussard de Chamborant, with his horse "Sultan", an oil on cloth by Pierre - Louis Bouvier, still decorates Madame de Staël' bedroom in Coppet.