Chris Roberson has 2 books in the Warhammer 40,000 catalogue, listed below in publication order with where each fits on the timeline.
Original summaries and chronology labels generated from the same catalog powering the atlas.
Chris Roberson
A novelization of the Dawn of War II video game following the Blood Ravens Chapter's Fifth Company as they defend a sub-sector against rampaging orks and the all-consuming hunger of a tyranid hive fleet. As the threats escalate, the Space Marines must hold the line while a deeper corruption festers within their own ranks.
667.M41 - 999.M41
era date, medium confidence
Chris Roberson
Three young recruits from rival cultures on a war-torn world are taken to become initiates of the Imperial Fists, where old hatreds must be forged into brotherhood. As they endure the gruelling trials of becoming Space Marines, their loyalty and resolve are tested against the enemies of the Imperium. A coming-of-age story about the making of an Astartes.
667.M41 - 999.M41
era date, medium confidence