Major Alok Mathur was born on 14 September 1969 in Jaipur, Rajasthan, into a military family. His father, Captain R S Mathur, was an Army veteran. Because of his father's postings, Alok studied at different places before joining Sainik School Chittorgarh. He subsequently trained at the National Defence Academy and the Indian Military Academy, Dehradun, and was commissioned into the Corps of Engineers in 1990.
During his military career, Major Alok Mathur served in challenging operational environments and also underwent commando training. In 2003, he was serving with 85 Road Construction Company in Arunachal Pradesh.
On 7 October 2003, while his troops were moving in the Kameng area, a group of militants launched a pre-planned ambush using automatic weapons from concealed positions in the jungle. Major Alok Mathur quickly assessed the situation and deployed his men to respond to the attack. During the intense exchange of fire, he was seriously wounded in his right hand. Despite heavy bleeding, he continued directing his troops and leading the engagement from the front.
Major Alok Mathur eventually collapsed and was evacuated by air to an Army hospital, where he succumbed to his injuries. He was posthumously awarded the Sena Medal for his courage, leadership, fighting spirit and supreme sacrifice.