At the time of the invasion of Yugoslavia by Nazi Germany, Adolf Hitler was uneasy with Mussolini's agenda of creating a puppet Croatian state, and preferred that areas outside of Italian territorial aims become part of Hungary as an autonomous territory. This would appease Nazi Germany's ally Hungary and its nationalist territorial claims. Germany's position on Croatia changed after its invasion of Yugoslavia in 1941. The invasion was spearheaded by a strong German invasion force which was largely responsible for the capture of Yugoslavia. Military forces from other Axis powers, including Italy, Hungary, and Bulgaria made few gains during the invasion.