First, I have never tried for a Diplomatic Victory before so I researched a bit how to get it and what are the keys. What I found out: Get a lot of Suzerains and Alliances to pile up Diplomatic Favor. Be sure to get the Statue of Liberty, help during emergencies and win the key votes.
So I want Envoys en masse, meaning I will go for the Apadana and Kilwa Kisiwani. Potala Palace would be nice for the extra Diplo Policy Slot and Országház for extra Diplo Favor. I also need a good balance of Science, Culture and Gold to support expansion. If I can get some other useful Wonders like Forbidden City, Pyramids and Colosseum, that would be nice too. Another key will be to get Cartography fast to meet civs and city states on the other continent(s), so I definitely want an early Coastal City. I also want at least 3 Okihtcitaw to scout my continent fast and meet everyone.
Ponding the start locations first - I chose between the Fox (+1F/+1G), the Chocolate (+3G) and the Plains Hill (+1P) to the NE. The Plains Hill didn't promise a lot of good inner ring or outer ring tiles from what I could see and the Fox neither. I moved the Warrior to see more tiles around the chocolate and was happy with I saw. Happy enough to spend one more turn moving before settling.
My build order in my Capital was: Okihtcitaw, Okihtcitaw, Settler, Monument, Campus, Settler
Science Order:
- Animal Husbandry, to find horses and get fox and sheep on-line
- Pottery, for my unique bonuses
- Writing, for an early Campus, I have a nice +4 Campus slot in the capital next to the fissures
- Mining, to enable chopping
- Masonry, because I discovered a nice Pyramids spot in my second city
- Archery, to fight barbs
- Bronze Working, to find iron and chop rain forests
Civics:
I pretty much beelined to Political Philosophy to get to the Apadana and fast Government Change
- Foreign Trade
- Early Empire
- Craftsmanship
- State Workforce
- Political Philosophy
My first five Tribal Villages gave me: Eureka Bronze Working, Inspiration Early Empire, Builder, Envoy, +20 Faith. I got a few more later in the game that gave me Gold if I remember well.
I was the first to meet Buenos Aires, but had to send envoys to the others.
My first Policies were Survey (to boost my unique unit, didn't prove too helpful though) and God King (to get a Pantheon). After I got my Pantheon I switched to Urban Planning & Discipline. I used the Builder 30% and Settler 50% as well once I was build that.
I sent delegations and traded as much as I could with the other Civs and made Friends with everyone. I haven't been allowed to set up Alliances yet.
After the first 100 Turns, I have settled 7 cities, am quite happy about the start and feel I'm progressing well towards my goal. I think the main problem will be to avoid other Victory Conditions. I'm far ahead the others in Science and Culture. The Era's are progressing very slowly. I have just discovered Cartography and have set sail to discover the new world.
Important events:
T5: Discover continent, Foreign Trade boost
T8: Met Suleyman, sent him Delegation and sold Chocs for 10 Gold + 1/turn
T10: Barb Camp to NW, beaten halfway down by Suleyman. Bought another 2/2 tile to work
T14: Cleared Barb Camp
T17: Decided to buy an Okihtcitaw as I didn't see a need for a Builder just now. One of my Okihtcitaw finds a barb camp that has been beaten badly by Babylon. Manages to kill the spearman and clear it for another 50g
T19: Met Sumeria, sent him Delegation. He has found a nice relic but is not prepared to sell it. Suleyman refuses to declare friendship
T21: Got my free trader from Pottery and sent him to Suleyman because I want to settle my next city between us to block him. This should speed up my settler thanks to roads once it is finished. Met Kongo and sent him a delegation as well
T22: Buys a Slinger to fight a Barb Camp to the NE
T25: Built my first Mekewap on the Grassland Hill for +1 Prod, +1 Gold, +1 Housing & +4 Era Score. Suleyman accepts my Friendship request
T28: Big Fail - lost my trader to a barb scout. I could have easily protected him with my Warrior next to him but was too unconcentrated. Discovers Geneva and Giants Causeway next to it. Builds a Farm on the Rice for Irrigation & Craftsmanship boost. My free builder proved very valuable
T30: Settled my second city, NE of Bananas just south of Suleyman -> starts to work on a Monument. This site has a +6 Campus tile between two fissures. My first Okihtcitaw gets his 2nd promotion and is now fast! I have reached 25 era points to secure first Golden Age. Barb Camp spawned just south of my Capital
T31: Pantheon thanks to 20 Faith from Village -> Fertility Rites. Religious Settlements was gone.
T34: Unmet player completes Great Bath
T38: Completes +4 Campus in capital, gaining 2 Envoys
T41: Assign Magnus to Second City to preparing chopping for Pyramids
T47: Starts to build Pyramids in Second City, Unmet player completes Stonehenge
T51: Wihkasko-Kiseyn finished Pyramids. Reassigns Magnus to Capital to prepare for Apadana
T52: Declares Friendship with Kongo and Sumeria. Upgrades Magnus
T53: Third City found on Coast to the SW of Capital. Not a very good site but I need a Coastal City to start researching towards Cartography
T57: Switches to Classical Republic
T59: Pingala appointed. Kongo has settled a city on the flood river to the SE. Need to replan my city building
T61: Suleyman defeats Lisbon. I wasted an envoy there. We enter a Golden Age and chooses Pen, Brush and Voice.
T66: Completes Apadana in Capital. Becomes Suzerain of Buenos Aires
T67: Suzerain of Geneva
T67-87: Government Plaza + Ancestral Hall in Capital, Settled 4 more cities, Suzerain of Babylon and Hongkong.
T87: Completed Hanging Gardens
T100: Completed Petra