On the 12 September 1914 the Earl of Lonsdale issued a recruiting poster asking 'Are You a Man or Are You a Mouse?' This call to arms was strikingly printed in his riding colours of canary yellow, white and plum red and 'was to be displayed in every possible place in Cumberland and West Morland'. So the 11th (Service) Battalion Border Regiment (Lonsdale) was born.
The Earl of Lonsdale submitted a proposal to the War Office to recruit a special Battalion for the Border Regiment, to be composed entirely of men from the hills and dales of Cumberland and Westmorland. The approval of the Army Council was given [War office, letter, No. 20/Gen. No. 3162 [A.G.I., dated 17/09/1914] and an Executive Committee was formed, raising soldiers in 3 localities:- Blackhall Racecourse, Carlisle enrolled by Major Binning, V. D. and Captain Sale; Kendal enrolled by Captain Wakefield and commanded by Colonel Haworth. V. D. and Lieut G. C. Rivington, Workington raised by Messrs Hodgson, Highton, and McKay. Blackhall became the Battalion Headquarters on 25th September 1914.
On 15th October 1914, the command of the Battalion was taken over by Captain Percy Wilfrid Machell, C.M.G. [of Crackenthorpe, Appleby], late 56th [Essex] Regiment.
The Battalion wore a silver cap badge of a winged griffin from the Lowther coat-of-arms. On 25th September it was announced that 'Messrs Redmayne and Sons, Wigton have been commissioned to make the tunics and trousers for the Lonsdale Battalion. This will be made from the dark grey serge manufactured in the Cumberland Mills.'
On the 5th November 1914 Colonel Machell reported that the strength of the local Lonsdale Battalion, all ranks, now stood at 881. Men were coming into Carlisle fast and he hoped to have made up the total of 1,100 within the next 10 days. The men he reported were of excellent physique and quality and their conduct exemplary, and they were making good progress in their training.
On 23rd November 1915, the Battalion left for France and landed at Boulogne and went straight to the Somme.
On the opening day of the Battle of Somme, 1st July 1916, the Battalion fought and lost over 500 casualties out of the 800 who went into action. The commanding officer Lt-Col. Machell was killed. Many of their dead are buried in the Lonsdale Cemetery at Authuille a village 5 kilometres north of the town of Albert on the D151 road to Grandcourt.
The Battalion was also involved in Operations on the Ancre and the German retreat to the Hindenburg Line in 1917. In early 1918, they were again in action on The Somme. On the 10th May 1918 the Battalion was reduced to cadre strength, with men being transferred to 1/5th Battalion. On the 13 May the remainder of the Battalion transferred to the 66th (2nd East Lancashire) Division and on the 31st of July 1918 the 11th Battalion was fully absorbed by 1/5th Battalion.