Being the commander of an impenetrable fortress has made Garcia a complacent man who has total faith that no one will ever be able to penetrate the "Umbrella of Artemis." He is also an ambitious man who is willing to subtly break treaty regulations to obtain that which could advance his position. The final word that could be used to describe him is prideful.
Not much is known of Garcia's past prior to the start of the First Alliance-PLANT War. When he is first introduced, he attempts to hold the battleship Archangel captive, attempting to keep the GAT-X105 Strike Gundam and its pilot Kira Yamato in his employ in order to overpower the Atlantic Federation. However, a sneak attack by Nicol Amalfi and the GAT-X207 Blitz Gundam damaged the asteroid fortress and allows the crew to escape. Sometime later, he would hire mercenary Gai Murakumo to protect the fortress before attempting to take him and MBF-P03 Gundam Astray Blue Frame for his own use.
Sometime later, the Eurasian Federation managed to acquire its own special Mobile Suit, the Hyperion as well as Canard Pars, a Coordinator who had failed to be the "Ultimate Coordinator". Most of his mission was attempting to find and take control of a Mobile Suit outfitted with a N-Jammer Canceller. However, when he finally got one, the YMF-X000A Dreadnought Gundam, it was too late: the Atlantic Federation already had the N-Jammer Canceller in their hands, forcing Garcia to attempt to arrest Canard for his loss.