It is known as Operation Iceberg and it lasted from 31 March to 22 June 1945.

It was part of the war took place in the Pacific Ocean between USA and Britain on one side and Japan on the other. 

The Japanese generals did not want to surrender so they continued fighting against the Allies.

The island of Okinawa was the last target of the Allies before they could plan an attack on Japan’s capital Tokyo.

The allies had 550.000 soldiers against 110.000 Japanese soldiers, civilians and kamikaze (suicide pilots). Also their fleet for this attack comprised of 1320 ships of every type and aircraft bombers.

The Allies started invading on the island. At first the Japanese defended vey fiercely.

Eventually the Japanese had 142.000 casualties, they lost 7.800 aircrafts and some of the generals committed suicide after the defeat.

The Allies lost 13.000 soldiers, 760 airplanes and 36 ships.

[Source: el.wikipedia.org]