The Battle of Saipan

On June 15, 1944, thousands of United States Marines came ashore on Saipan, beginning one of the most important and brutal battles of the Pacific War.

The island was only about 12 miles long, but its capture would tear a hole through Japan's defensive perimeter and give American forces a base within striking distance of the Japanese home islands.

For the Marines of the 2nd and 4th Marine Divisions, getting there meant fighting across beaches, cane fields, caves, mountains and shattered towns against an enemy determined to defend Saipan to the death.

The battle would last more than three weeks.

The Road to the Marianas

By the summer of 1944, American forces were steadily advancing across the Central Pacific.

The next objective was the Mariana Islands — Saipan, Tinian and Guam.

Saipan was especially important.

Capturing the island would provide the United States with airfields capable of supporting the new B-29 Superfortress, a long-range bomber that could reach the Japanese home islands.

For Japan, losing Saipan would bring the war dramatically closer to home.

More than 30,000 Japanese troops defended the island, using its rugged terrain to construct an extensive network of caves, bunkers, artillery positions and fortified ridges.

The Marines would have to dig them out.

The Marines Come Ashore

Before the invasion, American warships and aircraft pounded Saipan with bombs and naval gunfire.

At approximately 8:45 a.m. on June 15, 1944, the first assault waves reached the beaches.

The 2nd Marine Division landed on the left while the 4th Marine Division came ashore to the south.

Within less than half an hour, approximately 8,000 Marines were on Saipan.

Then the Japanese opened up.

Artillery and mortar rounds crashed into the beaches. Machine guns swept across exposed ground. Japanese guns hidden in caves and behind ridgelines had survived the naval bombardment and now fired directly into the landing force.

Marines pushed inland while additional troops, tanks, artillery and supplies poured onto the beaches behind them.

By nightfall, the beachhead belonged to the Marines.

But the battle had only begun.

Fighting Inland

Saipan was very different from the small coral atolls Marines had assaulted earlier in the Pacific.

The island contained mountains, cliffs, villages, sugarcane fields and deep ravines.

Every piece of terrain could hide another Japanese defensive position.

Marines quickly encountered caves filled with enemy troops. Flamethrowers, demolition charges, tanks and artillery became essential for destroying positions that could not be taken with rifles alone.

Japanese troops frequently remained hidden until Marines had passed, then emerged to attack from behind.

Progress was measured ridge by ridge and cave by cave.

On June 17, the U.S. Army's 27th Infantry Division was committed to the battle, joining the two Marine divisions already fighting across the island.

Together they began driving north.

The Battle for Mount Tapotchau

Dominating central Saipan was Mount Tapotchau, the island's highest point.

Whoever controlled it could observe much of the battlefield.

The terrain surrounding the mountain was brutal.

Marines and soldiers fought through ravines and steep slopes filled with Japanese defensive positions. Places that had once been anonymous terrain soon acquired names from the men fighting there.

Death Valley.

Purple Heart Ridge.

Hell's Pocket.

The names reflected the intensity of the fighting.

Japanese troops used caves and concealed positions to fire on advancing Americans, forcing assault teams to approach and destroy them individually.

Eventually, American forces captured the high ground.

From there, they continued north.

A Battle at Sea

While Marines fought across Saipan, an enormous naval battle was developing offshore.

Japan understood what losing the Marianas would mean and dispatched a major carrier force to attack the American invasion fleet.

The result was the Battle of the Philippine Sea, fought June 19–20, 1944.

American pilots devastated Japanese naval aviation in an engagement that became famous as the “Great Marianas Turkey Shoot.”

The Japanese attempt to disrupt the invasion had failed.

The Marines on Saipan would not have to face a major Japanese naval counterattack.

Now the battle for the island would be decided on the ground.

Garapan Falls

American forces continued pushing north while Japanese defenders were compressed into an increasingly small portion of the island.

The 2nd Marine Division advanced through Garapan, Saipan's largest town.

Once a thriving community, Garapan was reduced to shattered buildings and rubble by the fighting.

Marines moved through streets filled with destroyed structures while Japanese soldiers continued firing from hidden positions.

By July 4, Garapan had fallen.

The Japanese defenders were running out of island.

There was nowhere left to retreat.

The Final Banzai Charge

Before dawn on July 7, 1944, thousands of Japanese troops launched one final attack.

It became the largest Japanese banzai charge of the Pacific War.

Japanese soldiers surged forward in enormous numbers, crashing into American positions in northern Saipan.

Some were armed with rifles and bayonets. Others carried swords, grenades or whatever weapons remained available.

The attack overwhelmed portions of the American line.

Fighting became chaotic and extremely close.

Artillerymen fired their guns at point-blank range. Marines and soldiers fought with rifles, machine guns, pistols and bayonets as Japanese troops poured through gaps in the defenses.

For hours, the battle raged.

Eventually, American firepower stopped the attack.

Thousands of Japanese troops lay dead.

The organized defense of Saipan was effectively finished.

The Island Is Secured

On July 9, 1944, Saipan was declared secured, although isolated Japanese troops continued resisting long afterward.

The cost had been enormous.

Thousands of Americans were killed or wounded during the campaign, while nearly the entire Japanese garrison was destroyed.

The battle also produced one of the Pacific War's most tragic scenes.

As American forces reached the northern cliffs, large numbers of Japanese civilians fled before them. Japanese propaganda had convinced many that surrender to the Americans would result in torture or death.

Some civilians hid in caves.

Others jumped from cliffs into the sea rather than surrender.

Marines attempted to persuade civilians to come out of hiding, but fear and propaganda proved impossible to overcome in many cases.

The civilian deaths became one of the enduring tragedies of the Battle of Saipan.

Why Saipan Mattered

The capture of Saipan changed the strategic situation in the Pacific.

Japan's defensive perimeter had been breached.

American forces now possessed an island from which long-range bombers could eventually strike Japan itself.

The political impact inside Japan was immediate. The loss contributed to the fall of Prime Minister Hideki Tojo's government shortly afterward.

The Marianas campaign continued.

Marines invaded Guam on July 21.

Three days later, Marines who had just survived Saipan began landing on Tinian.

Within weeks, the United States controlled the major islands of the Marianas.

Construction crews immediately began transforming them into enormous air bases.

Soon, B-29 bombers would begin flying missions toward Japan.

The Legacy of Saipan

The Battle of Saipan demonstrated how far American amphibious warfare had developed since the desperate early days of Guadalcanal.

Ships, aircraft, artillery, amphibious vehicles, tanks and infantry operated together on a massive scale.

But technology could not eliminate the brutal reality of the fighting.

For the Marines on the ground, Saipan remained a battle fought one cave, one ridge and one shattered village at a time.

The Marines had crossed the Pacific to reach the Marianas.

After Saipan, the distance between American forces and Japan had suddenly become much smaller.

The road to Japan was open.