Jax Guilliman is Haxtes' older brother. Forcibly recruited into the Protasian resistance at age 14 Jax spent some time fighting against the Imperial invaders, but eventually the militia group became more like local warlords than defenders of liberty and freedom. Jax eventually stowed away on a cargo shuttle, ending up on the Maiden of Golgenna. He was nearly spaced by the crew, but Captain Simeon took pity and allowed him a place on the ship. Resourcefulness and stubborn loyalty meant that Jax rose steadily through the ranks, eventually becoming the Chief of Security back in 993.M41 - quite a feat for a man of only 26 years!

Later that same year the old Captain passed away and his son Corben inherited the vessel and father's Rogue Trader charter. The new Master and Commander of the Maiden was nothing like his old man - unused to space travel and completely lacking in character (at least when compared to the memory of his august father). Corben also flat out refused to use the charter was meant for and instead started plying the trade lanes of the Calixis sector. Income dwindled to almost nothing and crew began to find other employment. Jax stuck around and helped keep the crew together out of loyalty to the old man who had saved him back in the day.

Jax looks quite a bit like Haxtes, not too tall and with a wiry strength but little bulk - he's a couple of fingers shorter than his brother and somewhat heavier, but not much. He's even got the same haircut and facial hair as his brother, only his hair is dark blond instead of gray. He's usually dressed in a ship utility suit and an armored vest. As Chief of Security he rarely goes unarmed.