Why did Italian forces use Albania as a base for invading Greece in 1940?

In October 1940, Benito Mussolini launched an invasion of Greece from Albania, which Italy had occupied in April 1939.12

Mussolini’s primary motivation for this "separate" or "parallel" war was to assert his independence within the Axis alliance. Having been frequently restrained by Adolf Hitler regarding his ambitions in the Balkans—and annoyed by Hitler’s failure to inform him of German military movements in Romania—Mussolini decided to attack Greece without notifying the Germans. He openly admitted that his goal was to "pay back Hitler in his own coin" by achieving a quick, independent victory.12

The campaign proved to be a disastrous failure for Italian forces, who were halted and subsequently driven back by a Greek counteroffensive. This defeat ultimately forced Germany to intervene in 1941 to rescue its ally and take control of the region.123