However, as always it's not as simple as just sending a bunch of transports and their escorts and watching the invasion with a bowl of popcorn.  You see one of the Yor colonies, located in the Frey system, is way out of range.  I don't have any planets or starbases nearby.  The planets that are nearby belong to the Arceans.

I have got a constructor available in the Alenil system to build a starbase, so I look for a good spot and send it off with squadron of fighters so it doesn't get picked off by what little military the Yor still have.

Meanwhile, research on Pulse Cannons III is completed, and I take this opportunity to consult with engineers on how best to use these updated weapons:

The new Hornet V heavy fighter is fitted with three of the Mk3 pulse cannons, improving its firepower by 50%.

The Avenger II light figher carries an extra pulse cannon, doubling its firepower.

The Raptor III packs one extra pulse cannon (a modest 25% increase in firepower) but has a tougher hull than the previous frigate designs.

Remember how I destroyed a mining base built by the Yor?  Well, it seems that the Drengin have set up their own outpost there:

You can see here that I'm working on perfecting Warp Drive.  A bonus to speed will now be magnified thanks to the invention of Ultradrive, so it's difficult to ignore the opportunity to research it.

Also, thanks to the increase in revenue from tourism, I have a big fat surplus of credits.

My invasion forces finally arrive at Nesro IV, which is the only Yor colony which is in range.

Obviously, I could have used mass drivers to soften this planet up since it isn't very valuable, but the Yor forces here are not very numerous.  I go ahead with a conventional attack, which is successful:

As I said, not a highly valuable planet, but it's close to a number of galactic resources, which makes it a good place to support a mining starbase on one of those resources.

Woo, it's another exciting random event!

This turns a pair of formerly uninhabitable worlds in the Epsilon system into class 10 worlds.  Since I have a colony nearby, I start building  colony ship in the hopes I can get to one of them first.

Meanwhile, intelligence reports indicate that the Arceans have been busy with refits of their own:

While the design is still rather primitive compared to the Raptor III, let's not forget that the Arceans have been warring for a while now, and the battle-hardened crews of these frigates won't go down without a fight.  The Arceans also have the advantage of striking first, meaning that if their first salvo eliminates much or all of their opposition, they can win such a battle taking little damage in return or in fact coming away unscathed.

Having finished research on Warp Drive, I start looking into ways of improving the range of my ships:

It will take very little time to complete this research, and it will help in future to avoid the situation of being in a war with a race that is just beyond my reach.  Not that it will be much a problem after I have taken the last Yor colony, since I will then have colonies in just about every corner of the galaxy, but there's always the chance that a colony will fall into enemy hands, and this technology will make it far less likely that my ships run into supply issues during missions.

How come you don't use Information Warfare more?  You've plenty of cash, and it's such an effective force-multiplier.  

I didn't realize this was the case.  It doesn't hold for the player, though?  If one of your allies attacks another, you have to make a choice?

I've never seen this - if one of my allies declares war on the other, I can stay completely out of it (although if the victim is Super Organizer I still get asked for help). Maybe things worked this way in GalCiv I?

So I have my brand new invention matrices ready to go, what's next?

Well actually there's just one technology that leads on from Invention Matrix here, and that's Technology Progression III.  I could alternatively spend time working on other technologies, but this is the one which unlocks Expert Colonisation, which will allow me to research the advanced colonisation techs and make full use of some worlds.

Meanwhile the Iconians and Altarians sign peace treaties with the Drengin.  Could this be a new era of peace for the galaxy?

Well, definitely not for the I-League anyway:

The Arceans now have the largest number of colonies... next to the Terran Alliance, of course.

Sadly, it seems that peace was not to be, a scant couple of weeks after the peace treaty, hostilities between the Altarians and Drengin erupt again, and the Iconians declare war on the Drengin again:

Random event time!

I guess with it having been eleven years the archaeologists were bound to unearth one eventually.

Here's the intel report on the Ranger:

As you can see, it doesn't have the ridiculous triple-figure stats you would expect.  The mod changes the weapons and defences loadout quite a bit.  It's still immensely powerful at the current stage of weapons development, though.

But wait!  There's more...

Well finally the Torians have a military.  They only have one ship, but against a squadron of Drengin missile boats, my money's still going to be on the Ranger.

I complete my research, adding a few Invention Matrices to my planets along the way:

Still, I don't quite have what you would call end-game research output.  I sure wouldn't like to try slogging through Ultimate Space Weapons (that's almost five years of research) until I have more facilities.  Right now though, I need to be able to make better use of the planets I do have, since not all of my worlds are necessarily going to be doing research.

I've never actually played GalCiv I, so I wouldn't know for certain. But I am sure that if one of your allies declares war on an another ally in GalCiv II, you don't have to do anything. I've seen it happen often enough.

Okay well I guess it doesn't come up if one of your allies declares war on another, but think it does if a non-ally declares war (as you would expect).

The Arceans have occupied the homeworld of the Akilians, installing their own government which will of course be more sympathetic to the Arcean cause than the previous regime.

There is an economic boom which brings increased prosperity to the galaxy (like we actually need more of that!)

In August of 2239 I'm presented with an ethical choice:

Yes, send them packing.  Many of the colonies have well over ten billion people, and those people are going to be really unhappy if they all have to live in the same overcrowded cities.  There needs to be room for people to live, and the only way to accomplish that is to use the land we have as efficiently as possible.  We can't have primitive stone dwellings and old style labour-intensive farming taking up valuable space.

While it may seem overbearing and tyrannical to dictate where and how people should live, this is a decision made in the best interests of the citizens of the Terran Alliance, and if I allow citizens to revert to a pre-technological style of living then we may as well jettison out hyperdrives and shut down all the research centres, because a pre-technological society will have no interest in exploring the galaxy or expanding the knowledge of the human race.  There's the danger in letting people live as they please.

However, it seems I have been preparing for the wrong kind of attack all along:

The result of this unfortunate turn of events is that my colonies within the huge cheese (my affectionate name for the growing blob of Arcean space) are subject to immense cultural influence from nearby Arcean colonies.  My attempts to re-establish cultural balance are frustrated because I simply haven't explored any of the Xeno Business branch of the tech tree.

New Iconia is invaded by the Arceans, and as a result of the increase in native cultural power, the only remaining Iconian colony is subject to immense cultural pressure:

As the year 2240 comes to a close, the Terran colony on Arcturus III becomes dissatisfied and joins the Arcean Empire:

I guess they found something even better than Futurama because well, look.  My influence starbase here is barely having any effect at all.

I am saddened by the loss of one of my colonies and I have a curious thought.  Despite the power of native culture now, is it at all possible to get Arcturus III back?

We're about to find out.