I had played a rather strong opening, grabbing a religion and two early wonders, but now I needed to build some actual defenses to protect what I had while also expanding into the few good lands to the south as rapidly as possible. In other words, I had to pursue two conflicting goals at the same time (Expand! Protect what you have!) This is going to be fun. 
The Oracle had completed in 1040BC, with Metal Casting selected as the tech. Tenochtitlan went onto a much needed second worker afterwards. I met Mao at the bottom of the lake in 950BC (hmm, probably better than having to face Qin) which provided an additional incentive to get moving towards the south ASAP. Of course, rather than whipping the galley I needed at Teotichuacan, I instead chopped a forest and used that to complete it. Not a bad move - but still decidedly suboptimal. I should have saved that forest chop for the Forge that I would build there next. After building the worker and two archers, Tenochtitlan started a settler to grab part of the south. (I even have a line in my notes that literally reads "Gonna need some real defense here soon!" which I find to be amusing.)
The capital finished its settler in 625BC, and he hopped onto the galley I already had waiting along with an archer and set sail for the south. More importantly, Tenonchtitlan generated its first Great Person (a Prophet, obviously) which I used to build the Buddhist shrine.
I wanted to get the shrine up as soon as possible - not because I needed the income at this point (Buddhism only present in two cities in the whole world!) but because building the shrine for a religion greatly increases the rate at which it spreads. I tried to find the numbers on exactly how much it speeds up the spread and couldn't find it - but take my word for it, the increase is definitely noticeable! Hopefully Buddhism will jump out to some foreign cities and win me some allies in this harsh world. That's the plan, anyway.
Also notice that I'm researching Alphabet in the above shot. One of the things I learned from the Epic One reports was that I didn't get nearly enough out of trades with the other AI civs compared to some of the other players. Partly that was due to the fact that I had a runaway AI civ on my hands and there simply weren't all that many opportunities - but I also missed out on some diplomatic possibilities as well. Not going to make that mistake here; I'm heading for Alphabet very early on and plan to watch the F4 Diplomatic screen closely. Discover Alphabet in 575BC, and already there's a deal to be made: Meditation to Mao for Agriculture. Very nice. Also sign Open Borders with Mao in the hopes of increasing relations further.
Why am I being so nice to Mao diplomatically? Because I'm about to poach one of his city sites right out from under his nose!
Tlatelolco steals sheep and whales away from Mao. Even better, what I didn't know at the time was that there was a gold resource as well one tile south of that hill tile which I would be able to get within my cultural borders too. And look: grassland tiles! A plot of land that gets more than 1 food! What a coup! 
However - I don't have a prayer in the world of being able to defend this spot from Mao if he comes calling. One archer in the city, and reinforcements a half-dozen turns away by galley. Therefore, I absolutely have to do everything possible to make friends with Mao so that he won't call my bluff. I plan to send some missionaries a little bit later in the hopes of converting him to my Buddhist faith.
Uh oh, forget Mao, Caesar's calling my bluff! 
Yikes! See, this is why I've talked so much about needing to get defenses up and running. There is no such thing as a Farmer's Gambit in Civ4; if you can't defend what you have, the AI civs WILL come and take it away from you. The whole time I'm playing, a clock in the back of my mind has been ticking "better build some defense... time's running out..." Well, the alarm just sounded! Let's see what Caesar's bringing:
One chariot and one archer. I can handle that, but ONLY because I had been working on archers in Tenochtitlan for the last couple of turns. When Caesar launched the attack, there had been only one warrior in Teotihuacan, and his stack would have been more than enough to deal with that. The Roman units attack in 425BC; my archer kills the chariot but is redlined, while the Roman archer attacks and kills my warrior. I clean him up with my own archer:
That takes care of the initial stack - but I'm sure there will be more to come. (Also note that without that warrior there, I WOULD have lost the city.) Meanwhile, while this was going on I met Saladin, who had founded Judaism. Our relations were bad from the very start due to the conflict of faiths. I got the message that the Pyramids had been built in 475BC (wow, VERY early!) and when Saladin swapped to Representation the next turn, I knew who had gotten it. Virtually no chance for the human player to get it in my game, I wonder if anyone will make the attempt (?) Better Saladin get the wonder than one of the Financial civs though.
I discover Iron Working in 365BC and start research on Mathematics. There of course is no iron at the start position - but fortunately I don't need that for Jags. See, everyone bad mouths the Jags "oh, they're so much worse than regular swords!" while ignoring the fact that they are invaluable if you find yourself in a situation like this. Maybe the typical player just rerolls starts until they find themselves with iron? Heh. Anyway, I was very glad to have them here. As far as resources go, there was no copper, no iron, and no horses anywhere close to the starting position. Anyone going the military route in this game is going to be darned glad that they had resourceless Jags on hand!
On the very next turn, I spot a great trading opporunity with Mao and pull the trigger:
Alphabet for Math! Slightly favorable to the AI, but I'll take it in a heartbeat. Only had one turn's worth of beakers invested in Math, so I didn't lose much at all. That allows me to start researching - Currency! Another thing I noticed from the Epic One reports was that I delayed Currency for much too long, and I was not about to make the same mistake again here. Let's get those additional trade routes into play pronto! The ability to trade gold in diplomacy - and sell outdated techs to backwards civs for cash to fuel further deficit research - would also be a cornerstone of my gameplan. Teotihuacan finishes its forge and starts work on the Colossus (36 turns). That will also be enormously beneficial if I can land it.
Caesar sent two more chariots my way in 275BC, but I blocked off the shortest path to my civ with a Guerilla II archer on a forested hill. Rather than attack, the chariots detoured a longer path around to get to my borders. Wow. I tell ya, if you could have seen how far this AI has come from when we did our first Always War stress test last year... Anyway, they refused to attack the unit on ground of my choosing. By the time that they managed to reach the borders of Teotihuacan, however, I had some Jags in place to defend:
I love the Jag combat animation, by the way. Anyhow, I took those out and continued to await peace from Caesar. He would sign peace, but only for a tech - no thanks. I advance to the next turn... Wtf? What are those Roman units doing down by Tlatelolco?!
Wow. WOW. Wow. Anyone who doesn't think the Civ4 AI is vastly improved over Civ3's is out of their freakin' minds. Caesar saw that my colony down here was lightly defended, so he signed Open Borders with Mao and sent a stack after it. I THINK that I can hold against this, since there are now two archers down in Tlatelolco, but it's going to be close. Hmm. Maybe it's time to sign peace?
Another chariot and two AXES show up in the south as well. Sign peace, sign peace! I do manage to get a treaty with Rome, and Tlatelolco is thus spared from certain destruction. WHEW. I definitely got lucky there. Caesar wasn't really coming for me, he was in "limited war" mode, just probing my defenses and seeing what he could get. That, and the fact that he was so far away from me, is the ONLY reason why I was saved here. Still, I can't survive forever with this smoke and mirrors defense. I MUST get my hands on some copper or iron, and I MUST upgrade my defenses as soon as possible. I can't keep playing with fire here or I'm going to get burned.
While the fighting had been taking place, I founded a city on the red X shown earlier. Texcoco would become the quintessential fishing village, and I'll have more to say on it later. I also finally realized that I should be in Slavery at this point in time and swap to it. D'oh!
As far as iron goes, I knew there was some in the west and was planning to send my next settler there, but a barb city popped up on the spot first. Gah!
Bantu's a good city location, and I'll want to grab it eventually, but it's going to be a while before I can muster the resources to take a barb city like that. Instead, I now need a change of plans: there is a copper resource that I can reach on the lake, so I will found my next city there (in a truly awful location) in order to get my hands on SOME kind of metal. I'm definitely going to need axes if Caesar comes after me with his legions.
Take a look too at the religious icons in that picture above. Mao has adopted Buddhism! The religion spread on its own to one of his cities in 75AD and he converted the following turn. I still plan to send a missionary down there to convert his capital and solidify a friendly relationship. I've got to get Mao on my side or Tlatelolco is toast! (If turned to the Dark Side... a powerful ally he could become.)
Here's the map in 100AD:
I prefer the Flying Camera to the globe view, but I couldn't figure out how to access it while playing this game. (Kylearan later told me that it was moved from Ctrl-F to Ctrl-Alt-F... yeah, that makes a LOT of sense. 
) Tenochtitlan is trying to rectify my sad defensive situation by building some of my best unit, Jags. Teotihuacan is still pursuing the Colossus (it's been giving one up for the team this whole game, going Work Boat -> Galley -> Forge -> Colossus.) Tlatelolco is working on a library because it needs to win the border culture war with Nanjing, and Texcoco is still just starting out as a new fishing village. My next city will be going to the west of Texcoco, in order to pick up the copper you can see there (and wow is that bad land otherwise).
I sell Caesar's backwards civ Polytheism for 190g on the next turn and start researching Monotheism. Mao demands Priesthood in 150AD; whatever you say, buddy! I've already built the Oracle, so there's not too much of value there anyway. Meet Victoria in 175AD; she is the Hindu girl and already detests me for my religion. I can already see that if I manage to survive to the endgame, Vicky's going to be my primary competition in a spacerace (and it's unlikely she'll ever be a friend of mine). Of course, the good news is that Mao detests Victoria and vice versa, so maybe I can get the two of them to go at it...
I finish researching Literature in 350AD and start heading for Music. I've got to try for the Great Artist, and since I've got a monopoly on Literature, there's a good chance I'll get it! Tenochtitlan finishes a settler, starts Great Library - err wait, no, I need a library first. Whoops. In fact, I change my mind and pop out another archer first for my new city location just to be safe.
On the following turn, I generate my second Great Prophet:
That's the great thing about the Stonehenge/Oracle combo: guaranteed to get some early Great Prophets. Of course, if you don't want Prophets, then you've got a problem on your hands! I was more than happy to take Theology as the free tech, although someone else had already founded Christianity. On the same turn, I met Mansa Musa and swung a tech deal with him too:
I have no horses, of course, but most of the other civs already had Alphabet, so this trade actually was a steal for me. On the same turn, I also traded Metal Casting to Mao for Construction and 80g (I don't think anyone's going to beat me to the Colossus at this point, and especially on this map). These deals put me up among the leaders in tech - what a contrast from Epic One, where I mostly got left out of the trading and had to do all the researching myself! I did much better diplomatically in this game.
I whipped a library in Texcoco a couple turns later, so this is a good opportunity to highlight the quintessential fishing city:
With its two fish resources, Texcoco is also a perfect candidate for whipping. It's got a food surplus of EIGHT food per turn, wow! In other words, it will regrow those lost people in a hurry. I believe that I whipped this city about six or seven times during the course of the game, sometimes killing as many as 4 or 5 people at a time. And why not? They'll grow back. This city is all about working the sea; it has only one land tile in its entire radius. Yet Texcoco will prove to be an amazingly useful and productive city for me throughout the course of the game. I guarantee you'll never think about water tiles the same way after playing a game like this and seeing all that can be done with them!
Teotihuacan finally finished the Colossus in 450AD:
No, I am not deliberately replaying the same strategy from Epic One, honest! The land at the start was just so bad, my plan to overcome it was to build a maritime empire of the seas, in which the Colossus would be enormously beneficial. Up to this point, Tenochtitlan had been forced to build literally everything for my civ since Teotihuacan was stuck on wonder mode. Now I could finally start getting some military out of the second city and feel a little safer too. Excellent.
Tlaxcacla founded in a lousy site in 475AD to get copper - but at least it's on the coast. Meet Alex the next turn, and once again spot another tech deal that I can make:
Metal Casting for Monarchy and change. Alex actually goes to Pleased temporarily! Given our religious differences, however, I don't expect that to last very long. This is Alex we're talking about, remember.
I finish a library in Tenochtitlan in 580AD, begin working on the Great Library (13 turns). Since no one else appears to have Literature, and I have marble, I felt good about my chances for the wonder. Yet another trading opportunity for Metal Casting appeared the same turn, and I traded the tech to Mansa Musa for Code of Laws. Wow, have I ever gotten great value out of that or what? For whatever reason the AI civs didn't pursue the tech in the early going, and thus my Oracle build landed me the Colossus and three more techs (Construction, Monarchy, Code of Laws) in trades! I couldn't have written the script any better than that myself.
Music is discovered in 640AD and I land the free Great Artist! I save him for the moment, since the free tech is the inexpensive Drama. Texcoco gets whipped again for a forge, Monotheism sold to the pathetically backwards Caesar for 240g (!) After getting a border expansion at Tlaxcala in 680, I finally trade Monotheism and Code of Laws to Mao for Calendar. That makes me the undisputed tech LEADER!
This is not a trick screenshot; I actually have a two tech lead on Vicky, and more than that on everyone else. Now that's good tech trading! All I need to do now is nurse this tech lead long enough to build the spaceship. That may take a little while.
