300 AD (0): Sell Metallurgy to Germany for +68 GPT and 10 gold. Adjust science to 50 percent: Military Tradition in 7.
I think Murmansk is at a high flip risk to us.

We have it surrounded by 5 cities with temples, all of which will expand in culture again in 15-20 turns. New Cologne is also at a decent flip risk.
310 AD (1): 001: Horseman -> Library.
005: Horseman -> Horseman.
015: Horseman -> Horseman.
029: Worker -> Worker.
033: Worker -> Worker.
All 12 trebuchets miss the vPikeman at Merv.
A quick diplomacy check with Persia shows they have obtained Horses again somehow. Makes sense, since they had Knights earlier to throw at us. Seems that may not be quite done yet.
I switch a few marketplace builds to libraries. Might as well speed up research by a turn, or allow for us to slide back a notch on the research slider while we're still in the business of collecting beakers.
320 AD (2): 002: Library -> Marketplace.
004: Horseman -> Horseman.
006: Library -> Marketplace.
013: Horseman -> Horseman.
017: Trebuchet -> Trebuchet.
022: Barracks -> Musketman
This turnset I hit 2 of 12 times with the Trebuchets. It seems Merv has three defenders: two vPikes (now 3/4) and one rPike.
Knight Army defeats rPikeman in Merv. (26-16)
Knight Army defeats vPikeman in Merv. (27-16)
vHorseman loses to vPikeman in Merv. (27-17)
vHorseman loses to vPikeman in Merv, promotes Pikeman to elite. (27-18)
vHorseman loses to ePikeman in Merv. (27-19)
Knight Army defeats ePikeman (now redlined from Horseman suicides) in Merv. (28-19)
Maya captures the Persian city of Merv. Start on barracks.
IBT: A Persian galley lays the beatdown on a German caravel.
330 AD (3): 001: Library -> Horseman.
003: Horseman -> Horseman.
005: Horseman -> Horseman.
015: Horseman -> Horseman.
034: Worker -> Worker
036: Worker -> Worker
The resistance in Merv has ended.
IBT: The AIs are desperate for peace, no matter how many deals they break. Russia and Persia sign for peace.
340 AD (4): 001: Horseman -> Cathedral.
014: Barracks -> Horseman.
016: Trebuchet -> Harbor.
030: Settler -> Harbor.
I shuffle around specialists to get a few tax men to ensure we won't have more negative GPT than gold in the treasury.
There should be no more trebuchets under construction; if you see any cities building them, swap.
350 AD (5): 002: Marketplace -> Cathedral.
004: Horseman -> Horseman.
005: Horseman -> Horseman.
009: Harbor -> Barracks.
011: Barracks -> Horseman.
015: Horseman -> Horseman.
017: Trebuchet -> Barracks.
019: Harbor -> Worker.
026: Settler -> Worker.
Our deficit is suddenly covered by 20 turn +GPT payments for Gunpowder finally running out. We are at +45 GPT instead of -65 GPT.
I bombard Herat with a number of trebuchets, destroying the Barracks, Library, and knocking the sole vPike to 3/4. A rPike is revealed underneath.
Knight Army defeats rPikeman at Herat. (29-19)
Knight Army defeats vPikeman at Herat. (30-19)
Maya capture the Persian city of Herat, start worker.
vHorseman loses to vKnight. (30-20)
vHorseman loses to vKnight. (30-21)
vHorseman loses to vKnight. (30-22)
vKnight defeats vKnight. (31-22)
My only questionable practice is the suicide of Horsemen. We've lost 6 horseman this way during my set. I should be more careful, sorry. In both instances, we would have been fine with just 2 horseman suicides instead of 3 to increase the odds. At the moment, though, I mainly would like our Knights to survive when they attack, since they are irreplacable.
Also, thoughts on a campaign to take some of the Persian cities west of our main line of attack? It might be a decent endeavour for our Horsemen, though perhaps painful if 2 pikes/city. Your choice.
I've purposely left Merv unguarded to tempt the Immortal to step into the line of fire of the Trebuchets and subsequently, Horsemen.
There are two settlers on the eastern peninsula. One can go 24 of Murmansk to fill the gap of worked tiles (and add additional pressure

).
I also think it would be good to have a couple of muskets in the east, just in case. We've got a good collection of towns over east and I don't want a repeat of Persia in the west.
Turns are taking a long time now. It doesn't seem like they should, but they are. Beware.
If you want, you can re-sign Russia against Persia. Might be good. Depends what you're thinking.