Doctor Simon Petrovich was a renowned scientist and inventor specialising in the field of robotics. After a short career working for the Materials Group, he ended up defecting and offering his skills to the United Rebel Front. For years he and his comrades worked on a number of projects for the Insurrection, the 'Omega Group' being responsible for a number of breakthroughs that kept the remnants of the rebellion away from the UNSC. Following the end of the war Petrovich went into hiding and continued his work against the recovering UNSC through his top agent, Magnus. With the rise of the New Colonial Alliance in the turbulent years following the Human-Covenant War, he ensured that the URF worked with the organisation in secret, keeping out of open conflict and avoiding any direct contact with the UNSC.