After the bombing of Pearl Harbour in December 1941, New Zealand became intensely aware of its vulnerability to Japanese attack, and Northland was seen as the most likely launch point for an assault on Auckland.
That fear was heightened when British naval strength, the great hope of New Zealand's defence, was shown to be vulnerable with the sinking of the Prince of Wales and the Repulse days after Pearl Harbour. Hong Kong fell to the Japanese on Christmas Day 1941, and in February 1942 Singapore surrendered. Days later Darwin was bombed, and many feared Auckland would be next.
"Military attention turned to Northland, and efforts were made to strengthen the region's defence," Edwards said.
"In the early months of 1942, New Zealand's susceptibility to military attack was acute. One former member of the Home Guard stationed in Kaeo, for example, told the volunteers that they did a lot of bayonet training in the early days of the war because they only had six rounds of ammunition."
Secrecy was also important. Few people, for example, knew about the small military camp that was established close to the Treaty House at Waitangi, with its commanding view of the Bay of Islands, which was recorded in one of the archived maps, or the network of submerged mines at the entrance of Whangaroa Harbour.
The mines could be triggered individually or simultaneously from an ingeniously camouflaged bunker at the mouth of the harbour, which still survives, while artillery was installed in the Bay of Islands.
"The impact of this sudden threat of invasion can even be seen today in some of the north's current infrastructure," Edwards said.
"Kaitaia Airport, for example, was originally built for American long-range bombers that could reach parts of the South Pacific from their base in the Far North. Kaikohe's aerodrome was built for a similar purpose."
Other vital elements of Northland's military infrastructure, however, had simply faded away, like the airfield at Waipapakauri. Once home to No. 7 General Reconnaissance Squadron, and one of the most important airfields in the country, it was completely fenced off from the public as a high security defence area, and even had dummy aircraft to mislead would-be attackers.
The runway had now returned to pasture, with little obvious evidence of its highly strategic past.
The maps and documents reflected another dramatic change that occurred in New Zealand six months after the bombing of Pearl Harbour.
From mid-1942, thousands of US Marines arrived in New Zealand in preparation for the campaign in the Pacific, and were stationed in camps around the country, including in Northland, camps springing up at Warkworth, Maungatapere and Glenbervie.
"Wartime censorship prevented newspapers from writing about the American presence in New Zealand until November 1942, and even after that the news was strictly controlled," said Guthrie.
Anyone with any information about military bases in Northland during World War II, or other related information, is welcome to contact Bill Edwards on bedwards@heritage.org.nz or (09) 407-0471.
