This 'Marine's Marine' was best known for his deadly skill with a mortar tube

Leland Diamond joined the Marines in 1917 at the age of 27 to fight World War I. Diamond made a name for himself during that war as a Marine’s Marine. He was known for walking around without his cover, wearing his dungarees most places he went, and for having a loud and dirty mouth.


Don’t let the gray goatee fool you, Master Gunnery Sgt. Leland Diamond could whip you six ways from Sunday. Photo: US Marine Corps History Division

His uniform violations and occasional lack of courtesy were overlooked because of his conduct on the battlefield. He shipped to France as a corporal and fought at famous World War I battles like Belleau Wood and St. Mihiel. He earned his sergeant stripes and took part in the occupation of Germany before returning to the states and getting out.


A Collier’s drawing of Belleau Wood, circa 1921

He spent just over two years as a civilian, but the lifestyle didn’t suit him, so he returned to the Corps in 1921.

A few years later, he was sent to Shanghai, China to help guard U.S. vessels from attacks by Chinese criminals. He returned from China in 1933 but was sent back with the 4th Marines from 1934 to 1937.

When World War II kicked off, he was Master Gunnery Sgt. Diamond and the senior noncommissioned officer was an expert in firing mortars. He was especially well-known for his accuracy with small and medium mortar tubes.

Diamond and his unit were sent to Guadalcanal to help in the fight against the Japanese and the then-52-year-old proved his reputation. When a Japanese cruiser was spotted in the waters around the island, Diamond decided to engage it.

Marines on Guadalcanal

The Marines on Guadalcanal faced fierce Japanese opposition. Photo: US Archives

While a lot of legends surround the event, including the possibility that Diamond attacked it on a bet or that he landed at least one round straight down the enemy smokestack, historians agree that Diamond engaged the ship.

Japanese cruisers in World War II displaced between 7,000 and 9,000 tons and packed dozens of guns. Diamond was armed with a mortar tube and decades of combat experience.

Guess who won?

Diamond engaged the ship with harassing fire from his mortar. The ferocity and accuracy of his assault spooked the Japanese who withdrew despite the fact that it sported armor, cannons, and a large crew to counterattack with.

The old master gunnery sergeant was lauded for his actions but was still withdrawn from the fight a short time later. “Physical disabilities” resulted in the Marine being evacuated. After a short recovery in New Zealand, Diamond attempted to get back to his unit by getting orders on a supply ship to Guadalcanal.

By the time he arrived, the unit had left and he had to hitchhike his way to Australia. The Corps transferred him home soon after and assigned him to the training of new Marines, first at Parris Island and later at Camp Lejeune.

Diamond retired in 1945 and died 6 years later.