1.27 Predator
Link to Ancient Age spoiler
I'm going for a diplomatic victory. I entered the Middle Ages in 775BC. At that time I had eight towns (the capital and seven towns in ring 5), had not yet been in any conflict, and was in anarchy on the way to becoming a Republic.
Entering the Middle Ages
My free tech was Engineering. I gifted Ottomans and Greece forward and got lucky - their free techs were Feudalism and Monotheism respectively. I traded for both. I'd traded Republic to Greece and Rome. I also gifted it to Ottomans.
At this point I could be fairly sure at least two rivals were researching Invention. So I decided to research Theology. But not for a while - first it was time to rush some improvements and to begin thinking of war. When I became a Republic I had 29 units and had free support for only 9. Getting more towns was a priority. I eventually began researching again (Theology) in 530BC.
War on Zululand
The Zulu had two towns in my ring 5. Clearly a high priority.
Horsemen would fare poorly against the Zulu due to the Impi's defense strength and their speed which would block retreats. I also didn't want to rely heavily on Horsemen because I didn't plan to use Knights. I didn't want to lose research time (toward my diplomatic goal) on Chivalry, and didn't expect my rivals would research it for some time yet. So I decided my primary force would consist of Medieval Infantry, with some Horsemen backing them up for speed where that was useful.
In 610BC I had 6 Medieval Infantry and 4 Horsemen. Not huge but this is a Monarch game. I gave Zulu the Republic to stop them from pop rushing, then declared war and moved in.
Aside: I did not raze anything in this game because I wanted a Diplomatic win. Razing towns worsens the AIs' attitudes and therefore their inclination to vote for you. In a few cases where I very much did want to raze towns, e.g. when I captured some English towns which were inside my second ring, I captured the town, then starved it to size one, then allowed it to grow to size three so that the majority of citizens were German, and then abandoned it. Getting rid of towns that way avoided taking an attitude hit.
In 590BC I'd taken two Zulu towns to add to my ring 5. It was considerate of Shaka to build those towns at distance five from Berlin!
In 510BC England completed the Pyramids. I'd taken just one more Zulu town by then and of course I'd triggered their Golden Age. So I gave them peace for another town (leaving them with four) and repositioned to attack England.
War on England
In 470BC I gave England Republic, then declared war and moved in. At this date I had 12 Medieval Infantry and 5 Horsemen.
In 450BC I connected wines in ex-Zulu territory. Two luxuries at last, phew.
In 430BC I took London and the Pyramids, a major prize.
Eventually in 350BC I gave England peace for an island town in the far northwest (an island shared with three Celt towns), leaving England with just two mainland towns.
I started building a second ring at distance 9. There was room for a lot of productive cities at that distance and with courthouses they could become quite productive.
My research program was back underway and I learned Theology in 330BC.
War on Arabia
Of course I wanted to continue expanding. I preferred to leave the scientific Greeks and Ottomans alone as research partners. And also Rome because she'd been my best research partner so far. America and Celts were too far away, other Civs were between us. That left Arabia to be my next target.
In 210BC my troops were repositioned. I declared on Arabia and moved in. At this point I had 11 Medieval Infantry and 8 Horsemen.
This war went slowly because I didn't have a lot of units and those I had were slow moving. Still I did make steady progress. In 90BC I took a supply of incense.
In 10BC I got my first great leader. I set him aside to be used for a Forbidden Palace.
In 30AD I gave Arabia peace for two towns leaving her with just one.
While Fighting Arabia...
In 130BC I learned Education. I turned off research to used funds for rushing while waiting for someone to learn Invention.
In 110BC I at last was able to trade for contact with the three Civs on the other continent. They were very backward compared with the home continent.
I also traded to get Invention from Rome in 110BC. Although my rivals could be expected to research Gunpowder next I would not wait for them. I'd almost certainly run out of other useful research subjects (Banking and Astronomy) long before anyone learned Gunpowder. So I started researching it.
A Lull in the Fighting
At the end of the war on Arabia I had 6 Medieval Infantry and 7 Horsemen. Not a strong force. I preferred not to build many more MIs - they'd been useful but in the long run mounted units would be far better. I'd was on the research path to Military Tradition and decided to focus on getting that before another large war.
In 50AD my leader rushed a Forbidden Palace in the ex-Arabian region:
That wasn't the best place on the map for a second core. But it wasn't bad and I figured that getting my second region developing soon was more useful than waiting till I had a better location.
I learned Gunpowder in 10BC and gifted it to Rome and Greece so they'd start working on Astronomy.
I learned Chemistry in 90AD, Metallurgy in 170AD, and Military Tradition in 250AD.
Even during this lull I didn't stay entirely peaceful. In 210AD I had my meager forces repositioned near England's two remaining towns. I declared on her and took both towns in 230AD eliminating her from the game.
After learning Military Tradition it took quite a while to prepare for another war. Research remained my first priority, toward the Diplomatic goal. Maintaining fast research required all my income, not even leaving enough to upgrade my horsemen. My Monarch rivals weren't helpful, I couldn't get much gold from them. So I carried on researching while building Cavalry the slow way.
In 290AD I learned Banking and I needed Astronomy next, there were no other required techs available to learn. Rome and Greece hadn't learned it yet. So I started researching Astronomy. In 300AD Greece and Rome both knew it and I got it in trade.
I was able to maintain a four turn research pace, learning Physics in 340AD, Theory Of Gravity in 380AD, and Magnetism in 420AD to enter the Industrial Age. By then I was back in warmongering mode.
Second War on Zulu
In 360AD I had 8 Cavalry and 8 MIs in position to attack the Zulu. I declared and moved in, taking the Great Library from them immediately. That was a nice wonder to capture because it filled 1/2 of my requirement for a Golden Age.
In 380AD I got a second leader. I decided to delay using him for a couple of turns to get the best timing I could for my Golden Age.
In 390AD I eliminated the Zulu. My forces were up to 12 Cavalry and 7 MIs. And 7 Horsemen still waiting till I had the gold to upgrade them.
Entering the Industrial Age
In 400AD my second leader rushed Leonardo's, triggering a Golden Age in 410AD. I entered the Industrial Age in the following turn, 420AD.