When I ended my first spoiler, circa 1AD, I had just finished up my second war with Mansa. He only had 3 cities left, 2 in the northeastern corner of the continent, and 1 between Washington and Timbuktu on the desert coast.
Gandhi was blowing me away in technology, I hadn't met Hatty yet, and Roosevelt was dead.
I proceeded to build the much needed infrastructure to attempt to catch up to Gandhi in tech...and apparently, to catch up to Mansa in tech as well, because he surpassed me as well while I was pillaging his lands!
Slowly, my tech pace sped up, and around 1000AD, I met Hatty. She was less advanced than Gandhi, but since neither of them had anyone to trade with, they were teching slower than Immortal level AI usually does...albeit, much faster than me still.
Things passed quietly, for the most part, until 1500AD. A couple bumps were Gandhi managing to flip Washington from me, despite a bomb, several temples, a cathedral, and the Hermitage being built there...along with housing half my mobile army. Around 1500AD, I had managed to learn Chemistry and Steel, and in a calculated move, stopped research to upgrade my entire army. Timbuktu was starving and slowing flipping back to Mansa, and I had finally caught up to him in tech. I used my newly upgraded army of about 25 Grenadiers and 15 Cannons to declare war on Mansa...I knew I'd be in a bit of a mess when I did, because he had a higher power rating than me, and only 3 cities. I knew his cities would be massed full of rifles, but wasn't too worried about rifles in the field, thanks to the +50% of my Grenadiers.
I started moving toward Walata, his current capital(next to the Northeastern copper), and found that Mansa had made a pact with the RNGods...he quickly hit me with a number of rifles, killing 5 of my grenadiers while only losing 3 rifles. I reached Walata, after another wave of suicide rifles had killed another 5 grenadiers while losing only 3 rifles again. I bombed its gates and then killed all its defenders...except a lone catapult. I then sat there letting my medic 2 Immortal attempt to heal the rest of my stack. Mansa reinforced his city with another batch of Rifles, and I killed them all again, losing a couple cannons and a couple grenadiers...I left the Catapult alone again though. I repeated this twice more before Mansa reinforced with only a single rifle. I was glad too, because I'd lost enough of my grenadiers and cannons, that if he'd been able to last another turn or two I might not have been able to take the city until backup arrived(and backup was 7 or 8 turns away, as it was bombarding his coastal city in an attempt to prevent him from sending any of the 7 rifles there toward the rest of his empire.
I took Walata, and suffered no counter attacks. I then left a single grenadier there, and took his other Northeastern city, which was also defended by only 2 rifles. I proceeded backward, joined my two armies and the various reinforcements I'd received, mainly cannons, and took his last city.
I began rebuilding my infrastructure and preparing to improve the lands he had left me, when I was struck by something...why did I still have so much WW? I looked at the scores, and saw Mansa wasn't dead! He'd founded some city somewhere else in the world! I then managed to peace him for his WM, some gold, and rifling. I found out he had founded a city on a single tile island to the West of Gandhi's mainland empire(Gandhi had entirely settled the only major island)
I then looked at the tech screens, Gandhi had just built the Apollo Program, and knew there wasn't a chance in the world of me either catching up to Gandhi or Hatty, or of my winning a war with them...Gandhi had SAM Infantry and a Tank in Washington, while I had a handful of beatup Grenadiers.
So I decided to maximize my score for my loss....I built a half dozen workers, and began farming everything. I researched Biology next, farmed every single plains, grassland, and floodplain tile I had. I built windmills on every hill that wasn't part of my three main production cities. And I concentrated on making Gandhi and Hatty as friendly as I could, so I would survive till the end of the game.
Around 1840AD, I realized something crazy....I had passed Hatty in population! I was now the second person on the UN ballots! And since Gandhi liked asking for diplo wins, that meant, if I could get Hatty to like me enough...I could actually win! I began buttering her up, and got her up to +8...but couldn't get her to vote for me...she had +7 with Gandhi, and it was impossible for me to get any higher...every civic UN decision had been made, so I couldn't get the civic bonus with her. If I had, I would likely have won, because in 1904AD, Gandhi held a Diplo win vote, and with Hatty's vote, I would have won...instead, he launched his ship the very same turn.
I'm not sure how that would have turned out, two different people winning by different victory conditions on the same turn(since he was Sec-Gen, votes were done during his turn as well), but I would have almost won a diplo victory!

that would have been a true 'backdoor' diplo win, if ever there was one.
Instead, I likely got the latest spaceship loss, as Gandhi launched in 1904AD...pretty late for an Immortal level AI.