Mindanao 1945:
Battle for Mindanao
by Mike Bennighof, Ph.D.
February 2026

Panzer Grenadier: Mindanao 1945 is a Campaign Study, featuring 10 new scenarios based on the battles for control of the Visayas and Mindanao. You'll need Saipan 1944, Dragon’s Teeth (two pieces for one scenarios), Marianas 1944 and Leyte 1944 to play them all.

Mindanao is the second-largest island in the Philippines archipelago, and the southernmost large island. It fell to the Japanese in May 1942, when the American and Philippine defenders surrendered following threats that the Japanese would massacre the prisoners taken at Corregidor and Bataan if they did not. It’s a tropical island, noted for its bananas and pineapples, but notably lacking in militarily significant resources or industry.

As such, the Japanese did not assign their first-line forces to defend it. The 30th Infantry Division, at one time first-line outfit, had sent two of its three regiments to Leyte to be destroyed there, leaving the 74th Infantry Regiment behind, probably because it included a high proportion of deeply unwilling Korean conscripts. The 100th Infantry Division had been formed in May 1944 from an independent mixed brigade and some smaller units, plus another influx of recalcitrant Koreans. The Japanese occupation forces included a great many Koreans, and after the war the Japanese government would blame them for war crimes committed by Japanese forces. Few of the officers had combat experience, and most of the energetic and competent junior leaders had long since transferred away.

Both of those divisions defended the eastern part of Mindanao, including the capital, Davao. On the far western end of Mindanao, the 54th Mixed Brigade had responsibility for defending the port and city of Zamboanga and the tip of the long and narrow Zamboanga Peninsula.

Japanese dispositions in the Philippines, 1945.

The confused command structure on Mindanao didn’t help things. Thirty-Fifth Army had nominal control, but it had gone to Leyte to lead the fight against the Americans after they landed there in October 1944. The commander, Lt. Gen. Sosaku Suzuki, attempted to return to Mindanao, but he and many of his staff were killed by Allied air attacks as they crossed from Negros Island in small boats. The commander of Japanese air forces on Mindanao, Lt. Gen. Seiichi Terada, loaded himself and his staff aboard a Ki21 bomber (one of two operational planes left on Mindanao) and absconded to Japan. That left the air defenses to the one operational fighter plane left behind. The 35th Army chief of staff tried to take command, but with no staff and no radios, he could not contact the division commanders, and they didn’t listen to him when he finally did get in touch.

The Americans had a much clearer command structure, and much more effective troops to carry out the invasion. As in the Visayas, Robert Eichelberger of Eighth Army had overall command. The invasion of Mindanao would be undertaken by Franklin Sibley’s X Corps, with three divisions: the regular 24th Infantry Division, and the National Guard’s 31st (Alabama-Florida) and 41st (Washington-Oregon) Infantry Divisions. All of them had already seen extensive combat against the Japanese.

Assault on Zamobanga
The invasion of Mindanao began with an assault on Zamboanga; the long peninsula made it effectively a separate island that that’s how both sides had treated it in preparing their offensive and defensive plans. Two regiments of the 41st Infantry Division landed just to the north-west of Zamboanga City on the morning of 10 March 1945, right on top of an airfield which they quickly captured. They took the city on the next day, but it had been nearly destroyed by the U.S. Navy’s pre-invasion bombardment.

On the Japanese side, Maj. Gen. Tokichi Hojo’s 54th Independent Mixed Brigade did not try to defend the beaches or the city, pulling back into the rugged hills behind Zamboanga. As in the Visayas, Hojo had a large number of men (8,900) nominally under his command, but aside from his own brigade and the naval troops of the 32nd Guard Unit, these were rear-echelon personnel, and many were not even armed. About half of the total could be considered combatants, and as the Americans began to drive up the peninsula, they put up surprisingly stout resistance from well-prepared positions.

An 81mm mortar crew of the 162nd Infantry regiment lays down a barrage on the Zamboanga Peninsula. 23 March 1945.

The Americans brought in the division’s third regiment for a frontal assault up the center of the peninsula, into the teeth of the terrible terrain and strongest fortifications. On the 23rd they broke through, and Hojo withdrew his forces up the peninsula. The Americans pressed after them, and Filipino guerilla units blocked the roads leading northward, forcing the Japanese into the wild interior. By late April they had established a nest of resistance there, with the Philippine guerillas’ 105th Division surrounding them. A month later, Hojo told his men to disband and fend for themselves and then killed himself. Between the March-April battles, the retreat, starvation and disease, and constant attacks by the guerillas, these survivors had a much harder time than those in the Visayas. Only 1,385 survived the war, along with about 1,000 men captured earlier.

Battle for Davao
The campaign in Eastern Mindanao would be more complicated. American planners assumed that the Japanese would fight for Davao just as they had for Manila, house by house, and wished to avoid a landing in Davao Gulf and direct assault on the city. Instead, they landed on 17 April in Illana Bay, roughly 100 miles due west of Davao. Philippine guerillas had already secured the landing beaches, but the U.S. Navy shelled them anyway.

Having landed without opposition, the Americans began advancing along Highway One toward Davao. Lt. Gen. Jiro Harada of the Japanese 100th Infantry Division, dispatched two battalions, one Army and one Navy, to set up a blocking position at Digos, where the highway reached Davao Bay. Without firing a shot, they both fled to Mount Apo, a wilderness area and the tallest peak in the Philippines.

With the war winding down, Sibley and his boss Eichelberger had no desire to rack up needless casualties. The Americans advanced slowly along the “highway,” actually a poorly maintained dirt road, probing for Japanese defenses that did not exist. The lone Japanese battalion charged with delaying them mounted a few skirmishes before fleeing into the countryside; they would eventually re-join the 100th Infantry Division. The Americans reached the outskirts of Davao on 27 April and entered the city three days later, finally meeting resistance.

The Japanese held Libby Airdrome, six miles west of Davao, and the Americans skirted its southern edges to probe Davao itself. The Japanese could not be left there, but they showed no desire to leave, and the Americans would have to eject them. Fighting for the airdrome would last for five days, with the Americans finally driving back the Japanese, who had somehow discovered a will to fight and kept the dominating high ground nearby, rendering the airfield useless until these positions had been taken as well.

The Americans spread out along the shore of Davao Bay, on either side of the city, but to Harada’s surprise they did not try to outflank his positions just a couple of miles north of them. Harada had numbers, at least on paper, but the tally (rendered accurately by the Filipino guerillas) included thousands of support personnel. And given the decidedly third-rate nature of his combat troops the numbers did not tell the full story.

Expecting the Americans to push in his flanks, Harada pulled them back to form a deep horseshoe pointed at Davao. When the flank attacks did not come, the Japanese commander drew the conclusion that the Americans would attack up the middle, as they had north of Zamboanga, with little subtlety. Harada re-shuffled his forces to put his best troops in the center, backed by reserves. The expected American frontal assault began on 17 May, with one regiment of the 24th Infantry Division striking up Highway 1D toward the interior of Mindanao, and another pushing up the shore of Davao Gulf to meet up with the Philippine guerillas’ 107th Division.

The Japanese resisted surprisingly well, given their lack of supplies and supposed lack of fighting spirit. But American firepower told, and on the 29th Harada ordered a withdrawal to the north. The last Japanese troops pulled out of Davao City, and the Americans now had full control there. Harada had prepared a second line of defenses, which came under attack on 30 May.

Battle for Central Mindanao
The 31st Infantry Division had landed right behind the 24th Infantry Division and followed them along Highway 1 to the road junction of Kabacan. The 24th Infantry Division took a right to continue down Highway 1 toward Davao, while the 31st Infantry Division turned left to move northward into central Mindanao.

Lt. Gen. Gyosaku Morozumi’s 30th Infantry Division had responsibility for this sector. Morozumi had a regular infantry regiment (the 74th) from his own division, but most of the division’s troops had been destroyed on Leyte. In their place, he had some small independent Army units, and about 9,500 rear-area service personnel from both the Navy and Air Force. Some of these he formed into provisional infantry battalions, but he kept most of his force well north of the American landings in Illana Bay. Morozumi at first believed that to be a diversion, but ever after it became clear that the Americans had come ashore in great force, he feared another landing on the north coast of Mindanao.

The 1st Battalion of the 74th Regiment had skirmished with the Americans around the Kabacan road junction on 22 April, but Morozumi ordered them to pull back when the extent of the American forces there became clear. They moved up Sayre Highway, the main route through Central Mindanao, until Morozumi ordered them back southward again when he decided that the Americans were not advancing. By this point, few of his motor vehicles still worked due to lack of maintenance and spare parts (as well as American air attacks), and the highway itself had been disused since the Japanese occupation and become overgrown.

The Japanese stumbled into the oncoming American 124th Infantry Regiment at about 2200 on 27 April. The American regiment’s attached artillery battery opened fire with 105mm howitzers, and the Japanese battalion broke as the sun rose, with most of its men fleeing into the jungle, leaving 50 dead behind. The Americans lost ten dead and 25 wounded.

Heavy rains hampered the American advance, making it difficult for their engineers to repair the Sayre Highway – annual monsoon downpours (“Amihan” to the locals) had washed deep gullies through the roadbed, and vehicles could not follow the infantry. Sibley at X Corps ordered one regiment to continue northward to the city of Cagayan on Majacalar Bay, where the 108th Infantry Regiment of 41st Infantry Division had landed – exactly where Morozumi had feared.

The 155th Infantry Regiment headed north, with the 41st Infantry Division’s 162nd Infantry Regiment having marched overland from Zamboanga to take its place facing eastwards towards Davao and the Japanese 100th Infantry Division. The 124th Infantry Regiment would take a right turn on Sayre Highway, down a jungle track that the American command hoped would lead them into the 100th Infantry Division’s rear areas.

The Japanese Collapse
Once the Americans had broken through 100th Infantry Division’s lines, division commander Harada began planning a withdrawal into the inhospitable wilderness to the north-west of the city. The Americans opened a general offensive on 30 May, with 24th Infantry Division attacking all along its front with heavy air support. The Japanese resisted fiercely, especially in the center of their line, holding back the Americans at first. But by 9 June the division had begun to collapse, and the rout became general the next day. The Americans had cut off Harada’s planned retreat route, and the remnants of 100th Infantry Division pulled back directly northwards, breaking up into small groups who found shelter in the jungles as best they could.

North of Davao, Morozumi of 30th Division dispatched another battalion to delay the 124th Infantry’s eastward advance. They dug in at Maramag, a town along the Sayre Highway, and on 6 May the 124th Infantry, not having yet turned off the highway, ran into their roadblock. The Japanese held out for six days, fighting tenaciously before finally giving way. The delay allowed 30th Division to complete its eastwards retreat, well away from all of the advancing American columns. The division had turned in, according to the U.S. Army’s official history, “one of the sorriest showings made by any Japanese unit during the course of the war.”

Sherman tanks lead an American advance on Mindanao.

Morozumi withdrew his surviving troops into the rugged and isolated Angusan River Valley, but the Americans and Philippine guerillas followed him there. Fighting continued throughout June, with the Japanese division steadily breaking down as some men died and others fled.

Over 12,000 Japanese military personnel were killed in eastern Mindanao, and another 6,000 on the Zamboanga Peninsula. Unlike the campaign in the Visayas, there was no tacit truce offered, and Philippine guerillas continued to hunt down and killed Japanese survivors until the end of the war. Only 600 Japanese were taken prisoner. American casualties added up to 1,041 killed and 3,545 wounded.

The conquest of Mindanao fulfilled a political objective; the second-largest island in the Philippines had been liberated by American arms as promised. With their one operable airplane, the Japanese could do very little to hinder American operations. In strategic terms, the island’s conquest meant very little.

Order Mindanao 1945 Here.

Pacific Island Battles
Fight for Saipan, Guam, Tinian, Leyte, Luzon, and Mindanao: six maps, 671 pieces, 151 scenarios. One hundred and fifty-one scenarios.

Mindanao 1945: Battle for Mindanao by Mike Bennighof, Ph.D. February 2026

Mindanao 1945:
Battle for Mindanao
by Mike Bennighof, Ph.D.
February 2026