Tercio's personal history is shrouded in mystery. What is known is that he fought for years alongside El Cid, and had a reputation as the most bloodthirsty and skilled soldier in that band of warriors.
The Cainites of Dark Ages Iberia believed that Tercio had been embraced two years before his warlord El Cid died (some say as part of an effort to lure El Cid himself into the clan Lasombra), but what is fact is that after El Cid's demise, Bravo has spent decades laboring for the cause of the so-called Shadow Reconquista. Most of his time has been spent in the field, working to destabilize the various Muslim Taifa or to advance the orders of the assorted Christian Kingdoms.
For a time he stood beside the Prince of Toledo, as his advisor and general - a position that granted him a long reach among the Reconquista. But while an excellent tactician, Bravo was wedded to a strategy of unyielding attack that did not served him well in all cases, specially once his enemies gotten better at goading him into battles he could not win. Eventually he had to leave his post with the prince of Toledo under a cloud of disgrace, but that also meant Bravo was once again a free agent.
Over the next century his record has grown increasingly erratic, as personal hatreds and long-simmering feuds with other Cainites have taken precedence over his strategic judgement. As a result, Bravo has been more and more thoroughly isolated and his few confidantes note that he often rambles about being conspired against. However, while he is no longer as thoroughly feared on the battlefield as he once was, he is still a Cainite of significant personal power and charisma. His enemies would not dare to strike at him directly.
Dark Ages books states that Bravo's sire is one Lasombra called "Offa" and that Bravo himself is of the 7th Generation. However, in Chicago by Night 5th Edition, Talley, the hound, counts Tercio as one of his grandsires, listing Tercio Bravo as a 5th generation vampire, a direct childe of Boukephos. It is possible that the information contained by the Dark Ages books merely represent what was thought about Tercio at the time, and not his real background. It is also possible, however unlikely, that this is just an editorial mistake.