When I entered the Industrial Age in 130AD I immediately gifted Korea and Ottomans there as well, taking just Navigation in exchange. Korea got Medicine as her free tech, Ottomans got Steam Power. I gifted Baekje to the Industrial Age as well since she'd been my strongest research partner.
I waited a couple of turns, hoping those three Civs would trade the new techs around but only a two way trade happened. So in 170AD I bought Steam Power and started research again, working on Electricity. And as had happened in the Middle Ages, I found myself unable to achieve a four turn research rate. I made an ongoing effort to increase research capacity. Building Newton's in 260AD helped a bit.
Details of my tech progress through the Industrial Age:
170AD, trade for Steam Power
270AD, trade for Democracy
280AD, learn Electricity (7 turns)
280AD, trade for Medicine
340AD, learn Industrialization (6 turns)
350AD, trade for Military Tradition
380AD, learn The Corporation (4 turns)
430AD, learn Steel (5 turns)
480AD, trade for Nationalism
490AD, learn Refining (6 turns)
540AD, learn Combustion (5 turns)
560AD, trade for Replaceable Parts
590AD, learn Flight (5 turns)
630AD, learn Mass Production (4 turns)
670AD, learn Scientific Method (4 turns)
680AD, trade for Communism
690AD, trade for Enlightenment
720AD, learn Atomic Theory (5 turns)
760AD, learn Electronics (4 turns)
800AD, learn Motorized Transportation (4 turns) and Radio (ToE)
As you can see, I barely got my research rate to four turn techs a few times in this era. And I didn't do well in trades with the AIs. I guided their research and even gifted Baekje, my fastest research partner, 100gpt for part of the era. (As well as luxuries for the whole time.) But it didn't work out, they learned just Nationalism and ReplaceableParts for me. That's the minimum I expect to get from the AIs in this era even if I'm not helping them. Oh well, 800AD was still a nice date to reach Modern Times!
I timed a build of Theory of Evolution for 800AD to coincide with learning Motorized Transportation. That allowed me to learn Radio to enter Modern Times and to still have a free tech remaining from ToE, ensuring that I'd learn Computers immediately one way or another. Inter-turn, as soon as I learned Radio, I gifted Korea and Ottomans to Modern Times. They got Rocketry and Fission as their free techs respectively. I then used my second ToE choice to learn Computers.
I had 13 cities with prebuilds going for Research Labs. They completed their labs over the next few turns. But again I couldn't make it to steady four turn research. Details of my tech progress:
800AD, learn Computers, trade for Fission and Rocketry
860AD, learn Space Flight (6 turns)
870AD, trade for Sanitation and Amphibious War
910AD, learn Ecology (5 turns)
920AD, trade for Economics
960AD, learn Synthetic Fibers (5 turns)
1010AD, learn Superconductor (5 turns)
1050AD, learn Satellites (4 turns)
1090AD, learn Nuclear Power (4 turns)
1130AD, learn The Laser (4 turns) and launch!
In 230AD my Baekje allies destroyed Rajaputana. I'd taken over the majority of the Rajaputana territory by that time.
In 280AD I declared on Takeda and landed 12 Riders on their island. (I was still using Riders at this date, had 31 of them, many of them elite.) During my war on Takeda I started upgrading my Riders to Cavalry as they advanced.
In 370AD my last deal with the Mongols expired so I declared on them and attacked, finishing off their three remaining cities and eliminating them in 390AD.
Also in 390AD Tokugawa, who had already been at war with Takeda before me, finished off Takeda. So I was down to six remaining rivals at that date.
Around the same time the Ottomans were fighting Tokugawa and were faring poorly, so I gave the Ottomans a boost (horses and a luxury) to ensure they'd stay in the game - I wanted both Korea and Ottomans around at the start of the next era.
But that didn't stop me from taking over most of Korea
In 450AD I declared war on her. During this war I captured Sun Tzu's. A leader appeared in 490AD (I think it had been well over 50 elite wins since my last leader, wish I'd been counting) and rushed Universal Suffrage. I didn't particularly want that wonder but building it put an end to some possible AI cascades at the time. Another leader appeared in 500AD and I saved him, later on using him to rush Hoover Dam. In 510AD I gave Korea peace for her one remaining non-capital town.
In 580AD I declared war on Rome and began a small invasion of the other continent. This war was for no reason except score - I already had all resources and luxuries and any cities I gained in this war would be completely corrupt. This war started off poorly due a strong Roman counter-attack and one captured city flipping back. But my military, though small, had nothing else to do. So I pressed on for a while, gaining some territory and eventually giving Rome peace for a town in 720AD.
In 800AD, after trading for her free Modern tech, I again declared war on Korea. There wasn't much left of her from our prior war so I finished her off quickly in 830AD.
The only remaining rival on the starting continent was Baekje. I'd allowed her to grow so strong, and I'd devoted so little effort to my own military, that there was no point attacking her. Thus Baekje remained my friend until the end
She finished off Rome in 860AD and that was the last warfare in my game.
Here's how my world looked at that date (and it remained much the same in 1130AD when I launched):
It was nice to discover that one of my core cities, Shantung, could build Iron Works in this game! That simplified getting all of the later wonders. Here's how Shangtung looked when it was about to build the last spaceship part - it was one of the more productive cities I've had:
I was able to trade (usually old tech
) for luxuries throughout these parts of the game, maintaining 8 luxuries all the way. That gave enough happiness that I was able to handle war weariness (I stayed in Republic throughout) without needing to use the luxury slider - and that was something I really wanted to avoid with the research rate being a constant challenge!
I had great free tech luck in this game - Korea and Ottomans got different free techs at the beginning of each era. But my leader luck was I think the worst I've ever had. I do wish that the chances for creating leaders were a bit more predictable in the game.
Culture flips were amusing. I had just one painful one, in the Middle Ages. My culture rose rapidly after that. But in 480AD I lost a second city in a flip to Baekje, and then in 510AD they lost one in a flip to me! And during my attack on Rome one captured city flipped back to her despite my huge cultural lead.
In hindsight I might as well have taken out Baekje after the Middle Ages. That would have increased my score, and perhaps also improved my launch date by a few turns. (I'd have had a few more productive cities.) Baekje were a great help in earlier research but didn't help in the Industrial or Modern era.
Starting with two separated settlers in this game made for an interesting decision at the start and gave a nice initial boost. The squeezed start position offset that boost a bit, limiting expansion soon after starting. Baekje being a strong researcher but geographically in "our" area (i.e. where we could build productive cities) made for a difficult choice. And the map had many other nice elements, e.g. luxury distribution and the two minor Civs. Good fun!