Short answers, pulled from the story.
The Mediterranean and Middle East theatre began on the 10th of June 1940, when Italy declared war on the United Kingdom and France, and ended on the 2nd of May 1945, when all Axis forces in Italy surrendered. It had the longest duration of any theatre of the Second World War.
The Mediterranean and Middle East theatre covered the Mediterranean Sea, North Africa, the Horn of Africa, the Middle East, and Southern Europe. Its land, naval, and air campaigns were treated as one contiguous theatre of war rather than separate conflicts.
The theatre was initially driven by Italian aspirations to establish a new Roman Empire, with Mussolini seeking hegemony in the Mediterranean-Danubian-Balkan region and an empire stretching from the Strait of Gibraltar to the Strait of Hormuz. Mussolini described Italy as a prisoner in the Mediterranean bound by British and French control.
German forces suffered over two million losses, including those captured at the final surrender, and Italy lost around 177,000 men with several hundred thousand more captured. British losses amounted to over 300,000 men killed, wounded, or captured, while total American losses in the region were around 130,000.
Malta, located 60 miles from Sicily, was one of the first Italian targets and endured bombing and naval blockade that forced rationing on its inhabitants. Its air defence began with six Gloster Gladiator biplanes and was later strengthened by Hawker Hurricanes and 61 Supermarine Spitfires, allowing its forces to attack Axis supply convoys bound for Libya.
The theatre ended with the Surrender at Caserta and the unconditional surrender of German forces in Italy on the 2nd of May 1945, ordered by SS General Karl Wolff and General Heinrich von Vietinghoff. Mussolini had been captured and executed by Italian partisans on the 28th of April 1945.
The Greek Civil War and the first phase of the Palestine War were rooted in events during the Mediterranean theatre. The Greek Civil War began with clashes in Athens in December 1944, while violence in Palestine led to a civil war lasting until the British withdrawal in May 1948 and the start of the 1948 Arab-Israeli War.