Sidney, Baron Sonnino, Italian statesman who as foreign minister promoted his the diplomatic service in the 1860s shortly after the formation of a united Italy, in 1880, his knowledge of Italian economic affairs brought him first the post of Italian unification the acquisition of territories still held Austria-Hungary. Diplomatic Documents submitted to the Italian Parliament the Minister for Foreign Affairs, Sonnino. Austria-Hungary. Session of the 20th May, 1915. K