It was briefly raised in the 1910s and saw service in the First World War as part of the Wellington Infantry Regiment.

[1] At the outbreak of the First World War in August 1914, the decision was made to form a New Zealand infantry brigade of four battalions from the existing territorial regiments.

[2] Sir Walter Buchanan, a former MP for Wairarapa, was appointed honorary colonel of the Regiment in 1916.

[6] The Hawke's Bay Regiment remained in New Zealand for home defence during the Second World War and raised a 2nd Battalion in November 1940.

[10] The Ruahine Regiment was affiliated with the 19th, 22nd and 25th of the Second New Zealand Expeditionary Force and inherited their battle honours.