This is from memory, as the computer I played this game on has broken down...
Challenger save, with no clear goal on victory type. I would like to try warring since I don't have much experience in that area. For BTS, that is...
Was this really Immmortal? The start felt more like Prince or Monarch, perhaps due to the nice starting area with the gems for an early research boost and with plenty of room to expand.
EARLY EXPANSION AND THE BLOCKING OF TWO NEIGHBORS
I settled in place, researching Mining->BW while building worker-settler(chopped)-axes in the capital. Got a little lucky as I had already mined what turned out to be the copper hill while waiting for BW. City #2 was settled on the stone and built worker(chopped)-Stonehenge(chopped)-Great Wall(chopped). After that I used city#2 to spam settlers and later transformed it into a combined GP farm and science city working a bunch of specialists and cottages. I also got a lucky event while my capital was still of size 1 giving me +2 health in all cities.
My first axe went exploring to the north, stole a worker from Cyrus and razed a city defended by a lone archer. Then I spotted two Immortals in Persepolis so I sued for peace. A couple of other early axes found Bismarck to the south where he had founded a city 1S of the coastal horses. I stole the two workers pasturing the horses and razed that city, then proceeded to pillage all his other resources - and steal a third worker. Didn't make peace until quite some time later.
WARS OF CONQUEST: CYRUS
These two early expeditions gave me four extra workers that really speeded up my early expansion and allowed me to chop the Pyramids in Moscow as well. At the same time they stalled the expansion of my two nearest neighbors. I settled two more cities and captured one barb city, then started to build up an army for tackling Cyrus again. But here I probably delayed a bit too much. I was wary of a large mobile stack of cats and immortals that he had roaming quite close to our common border. I held my attack until they started laying siege to a barb city. But even though the barb city fell in one turn I still managed to take both Ecbatana and Persepolis before those units came anywhere close. They lost a couple of turns healing, then moved in zig-zag and killed a few stray barbarians while my units were moving through Cyrus's heartland just 4-5 tiles away. Not very impressed by the AI here... Anyway, I tried to press on against Pasargadae but had to call off the attack and make peace after a couple of unlucky rolls.
I developed my lands and teched to CS and Machinery, and became the first civ to build Macemen. With several cities pumping out cats and maces I redeclared on Cyrus and eventually captured his remaining four cities.
WARS OF CONQUEST: BISMARCK
I then shifted everything towards Bismarck except for a token defense consisting of obsolete units that were left to guard the northern front. Declared on Bismarck and marched through his lands unhindered, gaining another 7 cities to my sprawling empire (one city was razed).
I had a little fun war against JC during the conquest of Germany. I had spotted a whole bunch of roman prets and horse archers near former Persia - but only one catapult. So when JC backstabbed me I was prepared to lose a couple of cities before I could retaliate. But a few emergency upgrades and chopped walls and castle in Pasargadae saved me completely. I lost one pasture and one road, while JC lost some 20 units that just camped outside Pasargadae waiting for the one catapult to bring down the defenses. As I brought in stronger reinforcements one by one I could just pick those units off. Again, a moment where the AI seemed particularly clueless.
WARS OF CONQUEST: SALADIN
Having 19 cities and a huge army isn't optimal for research. Halfway through Liberalism I had ran out of money and had to watch as Wang Kon grabbed it in front of me. But I had a plan to get my economy running again. That plan involved capturing another 6 cities

, this time from Saladin. Specifically I wanted Mecca which had the shrine for Hinduism, the most widely spread religion and the state religion of me, Saladin and Gilgamesh. Wang Kon and JC were buddhists.
The war against Saladin had two phases, with a 10t peace treaty + some tech trade in between. In the first phase I captured two cities but spent most my Trebs and spies in the process. The second phase was much quicker, since Saladin nicely parked his SoD next to mine instead of attacking with the 10 or so catapults he had in it. After I had eradicated his SoD with minimal losses I could unhindered move around and capture one city after another. Stupid AI.
My economy kicked off again, helped by a Golden Age, and I was able to bump up my slider to 40% and trade for a couple of techs. This let me grab a monopoly on Chemistry and Military Science while my trading partner Gilgamesh was going for Military tradition. Meanwhile Wang Kon was pursuing stupid techs like Democracy, Communism, and Divine Right. You can see where this is leading, right?
Comparing my empire with Wangs, I had about twice as many cities but he had twice the research. My power and production was slightly better but I expected that to improve rapidly as my newly acquired cities came online and I kept producing units. So, again I shifted all my units back north while leaving only a token defense down in former Arabia.
WARS OF CONQUEST: WANG KON
The war with Wang Kon went well. He got Rifling on the turn before I reached Seoul, but CR3 trebs can handle even protective riflemen. The only tricky part was to get his cities into revolt as he had pretty high EP generation in his cities. I guess Democracy and Communism had unlocked some useful espionage buildings for him. Lucky for me, most of those buildings survived the change of ownership. In the end I enlarged my empire with another 13 cities, making it 38 total. This put me well above the population threshold for domination, though I still lacked some 10% land.
WARS OF CONQUEST: JULIUS AND GILGAMESH
With Wang Kon gone I suddenly found myself in the position of tech leader, although JC had Replacable parts and Rifling on me. Being eager to finish this game I declared war on both JC and Gilgamesh. I quickly took one city from Gilgamesh that was isolated inside my lands, but then I found myself making very little further progress. Gil had a very large number of Cuirassiers and it wasn't until I had stolen RP and Rifling from JC that I could deal with them efficiently. But by then Gil was close to Rifling and he was still unbroken, so I sued for peace and concentrated on JC instead.
Against JC I had to be a bit careful initially as he had Cavalry and Rifles against my Grens, Cannons, and Cuirassiers. And there was a huge stack that could likely take out any force I sent deeper into Roman territory. So instead I evacuated a border city and let the romans capture it with their SoD, and then immediately I wiped out the whole stack using my cannons and city raider grenadiers. It is interesting to see that this standard tactic for moving the fight to the most beneficial place does still work well in BTS.
After that I could go on the offensive and the roman cities fell one after another. I also captured the last Arabian city that was on the western map edge surrounded by rome. I completed Biology and put all cities on max growth to gain a few extra points. Finally, in 1675, when the first of the roman cities started coming out of revolt, I passed the land limit for a domination victory.
With only Gilgamesh left at the end I was considering going for a conquest victory instead but I decided against. It's not that fun to intentionally delay victory just to chase a more competitive date in a different category. But it appears now that that would have given me an award.

I could also have delayed my victory some turns to let my score grow as IIRC I had just learned Biology and my food production had suddenly increased dramatically. Maybe that could have put my score among the top three? I have no experience with milking the game so please help me understand how much extra population would have been needed for that. (I was 8000 points from the bronze, 50000 from the gold...)