I have been investigating what winning date I can achieve with exactly one settler pop. So far I have not been patient enough to wait for a map where I pop more than one settler. My best game up til now with only one settler pop resulted in a 590AD win. Since I believe the winning date depends highly on the number of settlers you are lucky/patient enough to pop, it would be interesting to compare this game to other games with exactly one settler pop.
For this particular case I have found three cities to be a good choice:
1st city: Capital
2nd city: Built from a 4000BC settler pop. I make use of 'Regenerate Map',to reject all maps that doesn't give a settler in 4000 BC.
3rd city: From capturing the capital of the enemy on the same continent. By choosing 'No City Razing' in the Custom Game menu, one can capture this city within the first 10-15 turns within razing it.
There is a trade-off between commerce from additional cities and the turns used to build settlers during which your initial cities don't grow. In one game, I tried to build two additional cities. This resulted in a slower initial tech pace, while the end-game pace was faster. The winning year was 710 AD, which is slightly worse than my three-city game.
There is also a trade-off between keeping the on-continent enemy alive for technology trading, and getting one extra city. I have found technology trading in this case to be non-efficient. Typically, researching alphabet immediately after writing, takes 15-20 turns. However, the technologies that can be traded from the AI after learning Alphabet, I can research myself using a total of about 25 turns if I research them immediately, and even less if I wait until they are needed. On the other hand, Alphabet can be researched in one turn if I research it near the end of the game when it is needed for Music (Great Artist). All in all, I don't see much advantage in saving the enemy for technology trading. On the other hand, the benefit from the captured city is non-disputable. Also, by eliminating the enemy on the same continent, I don't get any problem with the UN voting due to different religions.
City locations:
At least the capital should be surounded with at least 5 food plain tiles and preferably some forests and hills.
Research:
Immediate needs: Pottery(cottage),Writing(library),Bronze working(forest chops)
Main research path: After Bronze working, the path given by clicking on Mass media.
Detours: Metal casting(forge), Animal husbandry(pasture), Hunting(camp), Priesthood(oracle), Liberalism(free technology), Music/Litterature/Drama/Monarchy (free Artist for Mass Media)
The detours from the main research path are taken just before they are needed.
Workers:
One per city. This is not quite enough to keep up with the city growth, resulting in some unimproved tiles during the course of the game. On the other hand, by building only one worker per city, city growth can start earlier.
Improvements:
1. Cottages in food-rich tiles
2. Improved tiles with resources
3. Roads to connect cities and resources
General City builds in prioritized order:
1. worker
2. library (using forest chops)
3. warrior
4. granary
5. others (optional)
One city builds:
1. Forge (to build Great Engineer)
2. Oracle (to get free technology - used for radio)
Great People:
Great Scientist1: From using two scientists in a city with library - used for Scientific Method
Great Scientist2: From Physics - used for Electricity
Great Artist: From Music - used for Mass media
Great Engineer: From using one engineer in a city with forge - used for UN
Possible improvement:
Use pre-chops to get the UN quicker.
This srategy resulted in a 590AD win. Some people claims it is possible to have a BC win with only one settler pop. If that is true, I am obviously missing something.