Indomitus Crusade - For Vengeance and Reconquest: For all the efforts of Primarch Roboute Guilliman and his Officio Logisticarum, the first fully-fledged Indomitus Crusade Fleet departures took time to achieve. In the end it was Fleet Tertius that was first to rumble into action, its departure occurring several solar days premature due to the onset of a Khornate Crusade of Slaughter that was detected reaving its way through embattled Imperial space towards the Sol System.Fleet Tertius Fleetmaster Cassandra VanLeskus sought and acquired Roboute Guilliman's express permission to mobilise at once against this fresh threat; VanLeskus vowed that the servants of the Dark Gods would be given an immediate and spectacular demonstration of the Imperial vengeance that was coming for them.The details of the Battle of Machorta Sound are recorded elsewhere; it is enough to say that they served as a proof of concept of everything that Guilliman had intended his Crusade Fleets to be. Battlegroups Alphus, Betaris, Delphi, Haephestus, and Lambdax of Fleet Tertius drove headlong into a Heretic invasion that spanned several star systems. Despite initial differences and difficulties between several of the more disparate arms of the Imperial war machine, Lady VanLeskus led a crushing victory over the servants of the Blood God.So it was that Fleet Tertius launched from its void-moorings and straight into the annals of Imperial glory. Following Guilliman's grand strategic plan, the battlegroups of Fleet Tertius pushed on into the darkness, aiming to drive first into the Segmentum Pacificus and then to arc around into the vast reaches of the Segmentum Tempestus.Fleet Secundus set out next, its ranks spearheaded by the Battle Sisters of the Ebon Chalice and Our Martyred Lady alike, the prows of its warships aimed squarely towards the Eye of Terror. It would be the duty of Fleet Secundus to drive like a fist into the maw of the Segmentum Obscurus, its battlegroups aiming to retain a tight dispersal and a determined heading, and to allow nothing to slow the impetus of their counter-punch.It was a dangerous assignment, swiftly gaining the moniker "The Road of Martyrs," but it was just the sort of daring and aggressive offensive that humanity had to launch if it was to buy time to stabilise the Imperium Sanctus and ensure it was not overrun entirely.Only once Roboute Guilliman was sure that the machinations of muster and departure had gained their own unstoppable momentum, that the Officio Logisticarum were able to operate without his direct supervision, and that localised resistance to his plans had been utterly crushed, did he finally allow himself to take to the field in person.So did Fleet Primus leave the Sol System muster third, taking with it the single largest complement of Ultima Founding warriors and so-called Greyshields as well as Archmagos Belisarius Cawl himself aboard his mighty macro-barge, the Zar-Quaesitor.Fleet Primus comprised the most individual battlegroups of any Indomitus Crusade Fleet, and it set out not upon a single heading but instead diverged into several spearheads that further fractured as they spread out from Terra.Wherever the battlegroups of Fleet Primus surged into the fight they drove back the hordes of Heretics and xenos that threatened to overrun Mankind, relighting the beacons of the Imperium and leaving trails of space-borne debris and mountains of enemy dead in their wake.So it went on, fresh fleets mustering according to Roboute Guilliman's orders before departing into the darkness of the embattled Imperium. The Indomitus Crusade was not a force to conquer the galaxy as had been the Great Crusade before it.Rather this was a desperate and determined endeavour that, if successful, might just ensure the survival of the Imperium beyond the dark days of the Great Rift.So began the Era Indomitus, and with it Humanity's final furious attempt to outlast the hatred of the Dark Gods of Chaos.