Here's an idea for the start of the crusade. Does it sound consistent with the background?
When the infant primarchs vanished from Terra the Emperor used their genetic templates to create the legions. Does anyone know how long this took? At the same time he was probably consolidating control over the rest of Sol. The Saturnine fleet provided ships for the expeditions while Mars gave machine support.
The crusade began with twenty conquest fleets: one for each full strength legion. These included civilian support and heavy mechanicum equipment. Titan Legio Mars and the Skittari brought the big guns. Large numbers of colonists accompanied these ships, to spread Terran influence and skills.
A hundred seeding fleets also headed out toward the stars. Although one of the "old hundred" geno regiments accompanied each, these smaller fleets did not intend to capture worlds. Instead, they persuaded advanced human worlds to join the Imperium. If a planet refused, the fleet's astropaths simply contacted the Space marines and moved along. Weeks, months, or years later, the Emperor's finest fell from the skies.
Each seeding fleet carried a million colonists. Five thousand colonists landed on each uninhabited planet to pave the way for future attempts. Human worlds with no defense force (typically feudal or feral) were often colonized without any forewarning. The iterators and remembrancers integrated these worlds into the Imperial mindset over the following decades.
1) The Unification Wars seem to have included the conquest of the rest of the Solar system. It would not have been until then that the Mechanicum were allied with Terra.
2) There was no need of colonists in the early stages of the Crusade, and indeed the logistics would have weighed down the Expeditionary Fleets. The Crusade was about finding the old human planets and just reuniting them with Terra, not finding new undiscovered planets. Think of it as "reorganising", like going up and down your street making everyone dress the same and give you a bit of money each week... under threat of force! :D You don't bother with the vacant houses because they have no one to work for you.
3) IIRC the gene-tech proto-Astartes were used in the early stages of the Unification Wars, and the Primarchs were created (and lost!) long before the Great Crusade began. Therefore, the Astartes legions/regiments could *technically* pre-date the Primarchs, but they would have been replenished with "true Astartes" after the loss of the 20 Primarchs.
4) IIRC it states quite clearly in the early books that the Expeditionary Fleets were the first point of contact for ANY human civilisation that was discovered. They had diplomats and iterators among them who would negotiate surrender, with or without the military assistance which was on hand.
5) 'Decades' would be too long for compliance. The Emperor wanted worlds to be brought into the Imperium as quickly as possible - why play the waiting game when you have the largest military force the galaxy has ever seen?
Don't you think there would be far more primitive planets in M30 than in M41 seeing as the age of strife had just torn the galaxy apart? If you were the Emperor, wouldn't you use small groups of colonists to get these worlds back on the right path? There must have been many planets with extinct human populations in strategic locations holding valuable forgotten resources.
The Emperor's main problem was that he had a very small force. 200,000 space marines can only be in so many places at once, even though they were the finest warriors mankind had ever produced. :D They would need to spread themselves out a long way.
The early Imperium would have been very understaffed. There's no way the Sol System could provide enough manpower to send enough people to every world to enforce its will. However, the Imperium could afford to play the waiting game; at least for unimportant worlds.
What makes an expeditionary fleet? Each legion stayed in one fleet, right? Did they come in different levels, with some more heavily armed than others?
The exact composition of the fleets is not something I'd dare to comment on - can we get a green mod in here? :D
IIRC fleets tended to only have one legion involved, but each legion might have had several fleets.
|200,000 space marines can only be in so many places at once|
I suspect that at the very start of the Great Crusade there were far fewer marines present:
|QUOTE (Collected Visions)|
|The Early Space Marines were organised into regiments, each consisting of no more than a few hundred warriors. The Emperor named each of the twenty regiments..... As time went by the number of Space Marines quickly increased as the Emperor recruited men from among the recently conquered tribes of Earth. By the time the earth was totally under the Emeror's control each of the Legions could muster several thousand warriors.|
So it certainly appears that Legion sizes were smaller than the 10,000 per Legion that would be required to give a force of 200,000. In addition, several Legions had severe problems maintaining their numbers - the Emperor's Children numbered only 300 when Fulgrim was found, and the Thousand Sons only 1,000 when reunited with Magnus (admittedly these Legions had both had severe problems building up or keeping their numbers up). So I would imagine Legion numbers of 1,000 to 5,000 at the beginning of the Great Crusade.
|What makes an expeditionary fleet? Each legion stayed in one fleet, right? Did they come in different levels, with some more heavily armed than others?|
There are several examples of Legions separating their forces among several fleets in the novels (the Blood Angels fleet that first discovers 'Murder' carries 300 marines under the command of a Captain, and the Emperor's Children certainly split their forces at various points in Fulgrim, to give a couple of examples). Whether the Legions were split up at the beginning of the crusade is unclear - certainly they had fewer warriors, so they were more likely to stay on one fleet. As Shroud says, most fleets seem to have been mono-legion apart from occasional Legion representitives (such as Erebus).
Certainly the Emperor did not rely on the Astartes to conquer worlds, the Imperial Army regiments were quite capable of doing so themselves and often did so - see Legion where the army only requests Marine assistance when it becomes clear resistance is much stronger and more determined than they expected.
|Don't you think there would be far more primitive planets in M30 than in M41 seeing as the age of strife had just torn the galaxy apart? If you were the Emperor, wouldn't you use small groups of colonists to get these worlds back on the right path?|
The Great Crusade was primarily aimed at re-uniting colonised worlds. Certainly under-developed worlds would have had mechanicus representitives left to develop industry, and various Imperial representitives to develop the world generally (education, infrastructure, and so on - see for example the rapid development of Caliban noted in Descent of Angels and Fallen Angels). Of course, it also aimed to conquer Xenos worlds (Laeran, Murder, etc) both to eliminate their inhabitants as a threat and to clear them for human colonisation later - but it seems unlikely colonists travelled on the Expeditionary fleets themselves and there certainly seems to be nothing in the background thqat suggests this. They were probably dispatched from Terra or other Imperial worlds some point later on, once the planet had been pacified, in their own colony fleets.