First spoiler is
here.
I started to lose my focus after 1 AD. General plan of attack was finish off Alex - captured two of his cities: Thebes to the east with gems+cows and another city with pigs and a few hills. I also settled an additional 5 cities to get my total up to a more respectable 11. One new one along the southern coast with lots of food is my NE city, another one down there for cottages. Then another 3 along my western border claiming the resources in the jungle. These have been designated as production cities, especially the riverside one with lots of green tiles which will be my future IW city. (flat tiles with workshops > hills IMO).
The years up until 1500 AD were very peaceful, slowly working through Education, part Liberalism and on to Chemistry, while building infrastructure including OxU in Bulawayo (floodplain city north of capital). At 1500 AD I took a big break to think about the future. I reasoned that at this level, going for victory with only my 11 cities might be risky, especially since Im really aiming for diplo and my influence is a bit limited at present. So I grabbed Liberalism early and took Steel for the free tech. Ooops - no iron for cannon! Luckily there is an unclaimed iron amongst the desert near my friends Churchil and Mao, so I quickly send out a settler and found a city directly on top of it.
My HE city (city #2 just east of the capital) is producing cannon almost every other turn. Helpful Churchill even researches Rifling for me, which he trades to me. This is a pretty unbeatable combo versus Mehmeds outdated units - so I think! When I declare with what I think is a pretty big stack, I find it gets decimated by Mehmeds outrageously enormous bigger stack!

. So, the war is off to a bad start (all my fault, a spy for recon would have saved me so much hassle, no OB since the heathen buddhist hates my hindu self). Slowly I turn the tide, playing a bit more carefully, and bribing Mao into the war.
The war is going swimmingly after the initial frustrations - but then Churchill joins in and capitulates Mehmed. A real mistake here on my part, as I had the opportunity to bribe Churchill to make peace with Mehmed, but I chose not to. I actually had the option to capitulate Mehmed myself for many turns, but chose not to because then all bets are off as far as preventing Churchill from declaring on me himself. (Even though he is friendly, I dont think it matters if I have a vassal). With that, my hopes for a UN diplomatic victory are out the window (unless I want to take on the giant Churchill). So my focus now is claim as much land as possible, state property workshop everything and shoot for space.
Boudica is the most backwards AI and has no friends, so she is next on my hit list. This war went reasonably well, though I stalled a bit when I split my stack when I shouldnt have. A made a major blunder when I misclicked with my super-medic impi to attack Boudicas city. Her light brown colour and our yellow colour were just too similar for my eyes

. Again, Churchill comes along to spoil the party. And again I make a blunder - this time taking peace with Boudica 1 turn away from Industrialization. I learn the tech, and then see that with all my city taking, I do not have aluminium. Gah!
At this point Im still feeling pretty secure. All AI except Churchill are pretty backward, and I have a decent tech lead on Churchill. Time to gear up the economy, and properly develop my IW city + one other city in anticipation of the big SS Engine builds (watermills > workshops since Id switched to Emancipation). My early city placement comes back to haunt me, as I only had 1 production city (IW city) that was riverside and could build a levee

.
Churchill catches up... WAY to fast for my liking. At the same time I learn Fusion and still have Ecology+Genetics to go, he only has Fusion left. The only way I won this game I think is because of reasonably effective end-game production management that had all my parts built before Churchill, despite us both having all the necessary techs. Spaceship Victory in 1943 AD. Quite a nail biter! Thanks DS for a real tough, but enjoyable challenge
