T146 & 147 - Kingmaking
As expected, Xist declared war and pushed his stack to the walls of New Eire. There is also a Knight testing Skye, with more lurking behind. He also sent a small naval / amphibious force at Islay. The majority of my forces are still in the West, where Gira has been running mini-stacks up and down along our border laying down roads. I've had Machinery for a few turns and have a couple of Crossbows on-hand and have started saving for Engineering. Gira has recently grabbed Currency and is saving again for Machinery, while Xist clearly has had Guilds for long enough to build up a nice stack. I don't think he has Engineering yet though, so his movement is still somewhat limited.
Meanwhile:
Looks like TBS Libbed Nationalism and then rushed the Taj with a GEng, which just highlights the difference between the two continents!
Quick aside here on the naval defense before popping back to the main discussion. I had a Trireme here on the Crabs; Xist won the Trireme mirror match, but his was redlined. Settling party is on the way to found Isle of Wight on the hill; once the galley had dropped them it cleaned up the Trireme easily, allowing my own Trireme to take out the Galley and strand the Vultures. Islay has been whipping units to overflow-build a Forge, so has a decent garrison - 2 Axes and an Archer ... oh wait, I can promote that to a Crossbow.
OK, so with that over, let's talk about how I'm going to approach losing my mainland. I've decided that after what I've done to Gira in the early game, and given his relative position verses Xist, that I'm going to prioritise defending my East from the Knight & Vulture hoards, and all-but cede my Western cities to Gira. But not before I give him a bloody nose to wake him up...
I've had my eye on L'Escala for a number of turns; its garrison has always been comparatively small, but up until a couple of turns ago always included a Spear. I initially started to build up a 2-mover stack to grind my way through, but then was also looking at G2 Crossbows. I had built up 2 HA & 2 Chariots, each with 2 promos and had them hanging behind the mountain. I also have several other 1-promo Chariots in the area, so when he moved the Spear out last turn I positioned them in Lewis & Harris (before I noticed xist's stack on the opposite border).
So this turn when I find the Spear still missing and a Trireme sitting in port ... well I have to go for it. First HA takes C2 and dies redlining the Axe. This lets the second HA take Charge and get 70+ on the Catapult ... wins!

I send in my 3xp chariot to clean up the Axe:
As I expected, I can't raze it because I owned it for too long, but I've still put a dent in Gira and delayed his naval build-up. I decide to make it non-trivial for him to hit me back; I push a Spear/Axe pair into the city, and put an Axe over the HA so he can't get anything cheaply. Everything else in the area heads NE towards GB. Builds are now mostly War Elephants and Crossbows - filler Orkney is on an Archer (for upgrade). New Eire has 2 Praets as garrison, so to counter the Vultures whips an Axe for lack of a 6th Pop point.
Turn Roll
I had expected New Eire to fall and Mull to have been retaken, but there were no attacks between turns! Xist chose to bombard down the Walls at Eire, while Gira shuffled units around instead of committing.
Xist didn't even pillage the Silver at Islay!

That makes it worth attacking out this turn; Crossbow kills the first Vulture cleanly, the first Axe gets the remaining Vulture to 1/2 health so the other can clean up.

Great General born in GB, which we'll come back to later.
While we're here, I settle Isle of Wight on the island Hill as planned, and upgrade the garrison Archer to a Crossbow. Meanwhile Islay whips another Crossbow. I see a pair of xist Triremes on the horizon, but no follow-up Galleys in sight yet.
In the West, I leave the Axe/Spear pair in Mull, but pull everything else back - 2-movers head back to GB, while the Axe will garrison L&H for a turn or more. Crossbow also heads East and L&H (I think) starts another to be whipped next turn.
In the South, Skye has enough overflow to 1t another War Elephant, while Shetland whips theirs. I pull an Axe back into the city to give a second defender and deter the Knight from attacking. I add a Praet to Skye, but send the rest North. Most of my forces are now gathered at Ping-Pong to have an opportunity to counter-attack once xist hits New Eire. That city whips a Preatorian, while GB starts another War Elephant.
Back to the GG; I am most likely to load this onto a Galley ASAP and evacuate to Anglesey as an instructor. I will look for an opportunity to use it on land, but while I can throw up some nifty moves and counter-attacks in the short term, it won't be long before I fall to Xist & Gira's far superior production capacity. So planning for the "royal naval pain in the arse" portion of the game, I think that getting 2XP on a chunk of new ships is the right play. I may also evacuate some military units, but we'll see how it goes. You can also see that Engineering has been thrown out for Compass-Optics, as Pikes would not come soon enough to make a difference.