This model was introduced by GW in 2016, marking the 30th Anniversary of the Space Marines. The Imperial Fists were the VII Legion of the original twenty Space Marine Legions. Their Primarch is Rogal Dorn. The Legion remained loyal during the Horus Heresy, after which it was reorganised according to the Codex Astartes and divided into Chapters.
 
The Imperial Fists have maintained an intense rivalry with the Iron Warriors since prior to the Horus Heresy, with whom they share a specialization in siege warfare. The Imperial Fists are recognized to be among the most loyal Chapters to the Emperor and have been instrumental in holding the Imperium together during the bleakest of times with renowned stubborn resilience.