Lae is the capital of Morobe Province and is the second-largest city in Papua New Guinea. It is located near the delta of the Markham River and at the start of the Highlands Highway, which is the main land transport corridor between the Highlands Region and the coast. Lae is the largest cargo port of the country and is the industrial hub of Papua New Guinea. The city is known as the Garden City and home of the University of Technology.

The Battle of Wau, 29 January – 4 February 1943, was a battle in the New Guinea campaign of World War II. Forces of the Empire of Japan sailed from Rabaul and crossed the Solomon Sea and, despite Allied air attacks, successfully reached Lae, where they disembarked. Japanese troops then advanced overland on Wau, an Australian base that potentially threatened the Japanese positions at Salamaua and Lae. A race developed between the Japanese moving overland, hampered by the terrain, and the Australians, moving by air, hampered by the weather. By the time the Japanese reached the Wau area after a trek over the mountains, the Australian defenders had been greatly reinforced by air. In the battle that followed, despite achieving tactical surprise by approaching from an unexpected direction, the Japanese attackers were unable to capture Wau.