Japan has renamed the island of Iwo Jima, the site of one of the Second World War's most horrific battles, with its prewar name of Iwo To.

The new name, pronounced "ee-woh-toh," is used by the island's original inhabitants. In Japanese, the name looks and means the same as Iwo Jima — or Sulfur Island — but has a different sound.

U.S. marines of the 28th Regiment, 5th Division, raise the American flag atop Mount Suribachi, Iwo Jima, on Friday, Feb. 23, 1945. Iwo Jima has reverted to its prewar name Iwo To.
(Joe Rosenthal/Associated Press)

The name change was adopted Monday by the Japanese Geographical Survey Institute in consultation with the Japanese coast guard.

The name Iwo Jima came out of the war. The island was evacuated in 1944 as American forces advanced across the Pacific. Japanese navy officers moving in to fortify the island mistakenly called it Iwo Jima, and the name stuck.

The 1945 battle of Iwo Jima pitted 100,000 U.S. troops against 22,000 Japanese entrenched in tunnels and dugouts. Nearly 7,000 Americans and 21,000 Japanese troops were killed.

After the war, civilians weren't allowed to return and the island was put to exclusive military use by the Americans and the Japanese.

Locals were never happy with the island's new name, but the final straw came this year with the release of Clint Eastwood's Letters from Iwo Jima and Flags of Our Fathers, which reinforced the misnomer. 

In March, Ogasawara, the municipality that administers Iwo To and neighbouring islands, adopted the new name. Island residents and descendants of Iwo To evacuees petitioned the central government to follow suit, and they did.

Today, Iwo To's only inhabitants are about 400 Japanese soldiers.

An official map with the new name will be released Sept. 1.