Vyron Sector Crusade

The Vyron Sector Crusade was a large Imperial Crusade undertaken by the Astra Militarum Regiments of the Ashimar Nova Guard, including the Ashimar 43rd, which participated in the Imperial efforts to defend the Vyron Sector in the Ultima Segmentum from the Fifth Sphere Expansion of the Tau Empire.

Battle of Arappo (095.M42)
The Ashimar 43rd was deployed to the arid world of Arappo, where they fought alongside the regiments of the Arappan Ghost Riders to defeat the Tau invaders, who hailed from the Des'tron Sept.

Battle of Bleron (097.M42)
The Forge World of Bleron became a warzone when the planet’s Fabricator-General, Osmon Solitus, a radical obsessed with xenotech, turned the planet over to the Tau in exchange for access to their technology. Many of the planet’s Tech-Priests and their Skitarii waged a guerrilla war against the forces loyal to Solitus and his Tau allies for several years until Imperial Guard reinforcements spearheaded by the Ashimar 43rd arrived. The planet was retaken from the Tau, but at great cost, as the Ashimar 43rd suffered heavy casualties.

Battle of Lanévear (103.M42)
The Ashimar 43rd and the 16th Arappan Ghost Riders were called to the feudal world of Lanévear when a Tau force led by Water Caste diplomat Reshal arrived at the court of the planet's ruler, High King Hugon, and attempted to convince him to join the Greater Good. They ended up engaging the Tau and driving them offworld when the Tau tried to take the planet by force.