Both Alexandru and his other brother, Dimitrie, were originally chased out of Wallachia by the Crimean War: in November 1853, the country's invasion by Russia forced them to settle in Paris. Alexandru studied at the Military School of Saint-Cyr, but he is also known to have held a degree in the sciences. He secured an officer's rank in the French Army under the Second Empire, before being recalled to Wallachia by his father during the Italian War of 1859, in what was probably at attempt to maintain good relations between Wallachia and the Austrian Empire. This policy was disregarded by the prince's nephew Georges Bibesco, who went on to serve with distinction in the Franco–Mexican War.