Who designed the world's first combat bomber plane?

Major Gianni Caproni, Italian air services, War I period. there were earlier conversions of fighters and observation craft where crewmen tossed grenades at ground troops, but purpose-built bombers had to wait. The U.S. Army experimented with modified artillery shells hand-dropped from Curtiss craft as early as maybe l909. operating out of such bases as Fort Sill (Artillery school)