Suryavarman II

Suryavarman II posthumously named Paramavishnuloka, was a Khmer king of the Khmer Empire from 1113 AD to 1145-1150 AD and the builder of Angkor Wat, the largest religious monument in the world which he dedicated to the Hindu God Vishnu.

History
In Tomb Raider series Lara deducts King Suryavarman II (misspelled as Surya Varman II ingame) must have used the Red Stone to gain tremendous advantages in wars during his reign, and  probably the same stone is buried with him along with his treasure.