Tactica Imperialis is a Warhammer 40,000 background book written by Dan Abnett. It details four separate Imperial campaigns from the latter years of the Sabbat Worlds Crusade, with accompanying maps and descriptions of battles and important characters. The book is a follow-up to The Sabbat Worlds Crusade (Background Book), also written by Abnett and published in 2005. Tactica Imperialis was published in 2007 and is currently out of print.
Naxos - The Reef Stars 811.M41
Dark Eldar raiders mount occasional but highly damaging raids on the main habitation area of Naxos, Colony One, until a force of Space Marines from the Iron Snakes chapter, under the command of Captain Trokus, turns up to resolve the situation.
Lyubov - The Sabbat Worlds 778.M41
The hive world of Lyubov has been conquered by the forces of Chaos, including warriors of the Blood Pact. General Andreas Carnhide, a veteran Imperial Guard commander, has to draw together feuding factions of Guard, Navy and the Adeptus Mechanicus to retake the planet.
Rophanon - The Protean Ebb 990.M41
The ancient ruling nobility on Rophanon have their lands and power taken away from them when the Adeptus Terra decides to turn the planet into a retirement community for high-ranking clerks and a massive records storage facility. The council of Rophanon instigates a rebellion but Lord General Artemis Blythe just happens to be on the planet recovering from wounds suffered during a space battle. He leads the counterattack, which eventually becomes mired in a war of attrition. When Hive Fleet Leviathan emerges near Rophanon the Imperials withdraw and let the Tyranids destroy the planet before letting the Deathwatch pronounce Exterminatus.