Monger was 17 years old, and a private in the 23rd Regiment of Foot (later The Royal Welch Fusiliers), British Army during the Indian Mutiny when the following deed took place on 18 November 1857 at Secundra Bagh, Lucknow, India for which he was awarded the VC: Private Monger volunteered to accompany an officer, Thomas Bernard Hackett, whom he assisted in rescuing a corporal of the 23rd Regiment of Foot, who was lying wounded and exposed to very heavy fire.

Hackett, whom he assisted in bringing in a Corporal of the 23rd Regiment, who was lying wounded in an exposed position.

He is buried at Hastings Cemetery, East Sussex, in section H, grave E-18 common.

A blue plaque is displayed on his former house in Tower Road, St Leonards-on-Sea, East Sussex.

His Victoria Cross is displayed at the Royal Welch Fusiliers Museum at Caernarfon Castle, Gwynedd, Wales.