The 14th Ferozepore Sikhs were officially the 14th Regiment of Bengal Infantry (The Ferozepore Sikhs). They served in the 3rd China War (Boxer Rebellion), in 1900. As the 14th King George's Own Ferozepore Sikhs, the regiment served in Gallipoli and Mesopotamia during World War One (1914-1918).

Source description:

British and Indian officers (including two from the 45th Rattray's Sikhs) pose for a photograph before leaving India for China. Jemadar Bhagwan Singh is seated on the far left of the front row. Of the 28 men shown, 12 are British officers who all wear turbans like the men they commanded. This photograph belonged to Major G.D. P. Swinley (the only British officer without a moustache) who died in May 1915 during the Gallipoli campaign.

This photograph was also published at the following link ([1]) with this description (translated by DeepL from the original Chinese text):

The early Sikhs in Singapore were mercenaries who set up a barracks for Indian soldiers at the junction of Ao Nang Road and San Kiu Road, which was officially named Sepoy Lines, or Sipai Poe in Chinese, from the word Sipai, meaning soldier. Since they belonged to the Bengal Regiment, the Sikhs have long been called Bengali, and there is another race in India called "Bengali", the two "Bengalis" are often confused. The two "Bangalis" are often confused.