Southeast Asia Treaty Organization
De Vega was born in Manila, Philippines on February 1, 1931 to Jose Cruz de Vega and Vicenta Vinluan. He graduated from the Manuel L. Quezon University with a Master of Arts degree in History and a Bachelor of Arts degree in History, cum laude. He obtained his Doctor of Philosophy in History from the University of Sindh in Hyderabad, Pakistan in 1962 as an exchange scholar of the Southeast Asia Treaty Organization (SEATO).