From Halopedia, the Halo wiki
Childhood and Spartan training
He was left orphaned after his parents were killed by the Covenant. He was sent to an orphanage, where he lived until he volunteered for the SPARTAN-III program in 2532. He hoped to get revenge on the Covenant for killing his family and destroying his home planet.
Robert was sent to Camp Currahee on Onyx to be trained with Alpha Company by then-Lieutenant Kurt Ambrose and CPO Mendez. On the first day there, he pushed Shane-A112 out of a Pelican during a Falcon Wing descent exercise. When they both landed on the ground, Shane attacked him, and had to be subdued by CPO Mendez and a drill instructor.
Combat deployments and death
Robert eventually graduated from Alpha Company, which was then deployed on numerous battlefields, against both Insurrectionists and the Covenant. These included the insurrection of Mamore, the Battle of New Constantinople, skirmishes in the Bonanza asteroid belt and the Far-gone colony platforms, as well as half a dozen other engagements over a span of nine months.
He was killed during Operation: PROMETHEUS along with most of the 300 Spartans of Alpha Company. He was killed by a plasma bolt to the stomach from an Elite's plasma rifle, while trying to pull an incapacitated Jane to safety. Kurt, who later viewed the footage from one of the Spartans' helmet recorders, was profoundly distraught by his death, along with those of the rest of Alpha Company. He attributed their demise primarily to loss of unit cohesion during the battle and later made an effort to emphasize the importance of teamwork when training the next batch of the Spartan-IIIs.
List of appearances