Chris is one of the two main protagonists in the first Resident Evil game, the other being Jill Valentine. Redfield returned as a playable character in Resident Evil Code: Veronica, where he must search for, and ultimately rescue, his younger sister, Claire. Chris returned again as the main protagonist in Resident Evil 5, where he works alongside partner Sheva Alomar to search for his old partner and friend, Jill Valentine. Chris is also playable in Resident Evil: The Umbrella Chronicles, Resident Evil: The Darkside Chronicles and in the Resident Evil 2 Battle game. He will be appearing with Jill in the next installment of the main series; Resident Evil Revelations.

Source: Wikipedia, "Chris Redfield", available under the CC-BY-SA License.