[3] In the years 1881–1914, the two regular battalions saw overseas service in Hong Kong, India, Singapore and South Africa, with the regiment receiving battle honours for actions in the North West Frontier Province and the Second Boer War.

[8] The 2nd Battalion, which had been in Alexandria, returned to England and then landed at Le Havre as part of the 24th Brigade in the 8th Division in November 1914 also for service on the Western Front.

[8] The 1/4th Battalion landed at Suvla Bay as part of the 162nd Brigade in the 54th (East Anglian) Division in August 1915; it was evacuated from Gallipoli in December 1915 and arrived at Alexandria and then served in Egypt and Palestine later.

[9] On 17 October 1935, a Royal Scot Class locomotive of the London, Midland and Scottish Railway was named The Northamptonshire Regiment at a ceremony at Northampton (Castle) Station.

[13] The battalion saw active service as part of the British Expeditionary Force (BEF) in the battles of Belgium and France and had to be evacuated at Dunkirk.

2nd Battalion then joined the forces sent to invade Madagascar in May 1942 and then travelled to India and overland to Persia (now Iran) and Iraq in September of the same year.

It travelled to Egypt and next fought in Sicily and Italy before being transferred to North-West Europe as part of 21st Army Group in February 1945.

Despite being raised for war service, it remained in the United Kingdom until February 1945 when, now as part of the 115th Infantry Brigade, it went to North West Europe.

The cap badge featured a representation of a castle and key and the battle honour "Gibraltar", earned by the 58th Foot in 1779–1783.

Below the castle was a scroll bearing the honour "Talavera", and the badge was encircled by a laurel wreath earned by the 48th Foot in 1809 during the Peninsular War.

[26] The scarlet and blue officers' mess dress worn in the 1930s included collar and cuffs in the buff of the 48th and waistcoats in the black of the 58th.