Forgive me, there's a long rant here. This happened this morning and it has me seriously puzzled 
So here's the setup: Huge, Terra, Marathon - started with 14 AIs plus me (Inca)
Que rushed from the word "Go" and Wiped out Russia, India, America, and France by 2000ish BC and had to stop to stabilize my economy. (That and any AIs further away were teching up beyond what my Ques could handle)
Germany had a lousy start on a penninsula and was immediately culture-locked by Mali. Lacking any turf to expand, no tech, and no resources Bizmark quickly decided life would be better as my vassal. This was around 500ish BC (I forget, long time ago now
)
Fast forward 1200 years or so. Power standings:
Me (about 1000pts ahead of #2)
Ottoman
England
Egypt
Greece
(Everyone else - Japan, Korea, Mali, Spain, Vikings, )
Germany
I beat the AIs to Astronomy and had the majority of North and Central America settled already. Most of South America got snatched by the Vikings and Ottomans.
Egypt had a few wars with Greece and, despite tech and power parity with England and Ottoman, negotiates a peace with Greece - and promptly decides to hop on board the Inca Train becoming my vassal somewhere around 1000AD.
Mali does the same a short time later. Alexander, in a snit realizing he can't go after Egypt or Mali because of me decides to declare on Ottoman. Mechmed who is on tech/power parity with me just kinda laughs and promptly stomps him into putty. Greece capitulates and becomes an Ottoman vassal.
By now Tokugawa is Furious with me (of course) so I decide to beat him to the punch by invading. There was absolutely no doubt he was coming for me and waiting for it would be silly - and at this point I was gunning for a Domination victory. It's about 1400AD or there-abouts.
In just a few turns I've all but eliminated Japan. Much to my surprise he had a brand new city on the very southern tip of South America that I didn't know about and, being out of position to finish that city, decide to negotiate a peace with Tokugawa so my war weariness had a chance to bleed off. By the time the 10 turns are up I'll have enough force moved down from North America to finish his piddly little size one newbie capital.
I turn my eyes towards Korea, the next weakest foe. I position my forces and invade on the same turn I wipe out Tokugawa. I crush 4 of Korea's cities on the opening turn of the war leaving only 5 left. A few short turns later I've island-hopped my way through 2 of those cities when...
Victoria has declared war on you!
Ack! Where did this come from!? I didn't want a war with Victoria - she was close to me in tech and power and all my offensive units were tied up! Gak! Turns out Korea pulled a fast one and capitulated to Victoria becoming England's Vassal .... and my enemy.
Mali, Egypt and Bizmark all being good vassals promptly declare on England. Knowing I had no offensive units and depleted defenses in my border cities (having robbed them to attack Korea) I know I probably can't stop the SOD Victoria is gonna send my way. She doesn't have gunships or tanks but she does have scads of Cavalry and cannon.
This is where having a tech lead is handy. A few fast bribes and Isabella declares on Victoria. Ragnar declares on Victoria and... *gasp* for a lousy 2k Ottoman (and Alexander as a vassal) declare on Victoria.
World War One has begun. I love this
Ottoman at this time had tech parity with -me- and I was always worried he might come after me and with Alexander as his vassal and all my offensive firepower already tied up I woulda been snuffed.
Now... I told you this entire story so I could tell you this one:
It's the late 1700s. I managed to fend off a much weaker English assault than I anticipated was coming. (Egypt and Ottoman shared a border with her and immediately mauled her border cities forcing England to go Turtle and pull all her units back to defend) I blast through all but the last remaining Korean city and lacking offensive units to take the fight to Victoria I do the next best thing - send in a squad of gunships to crash her economy and keep her attention away from my own borders.
That was last night.
This morning? This morning got even weirder
The situation: Korea has but one city left in the New World, and I own the new world, allowing me to free up all of my air and naval units to move on England. They'll take ten turns to move from Korea's last city to England's coast (no ocean route through Europe/Africa - gotta go all the way around
)
Anyway, in 10 turns or so I'll be hitting the beaches and leading the way will be a 40+ xp Great General Tank that is totally unstoppable. Spain, Ottoman, Egypt, Mali, Germany, Vikings, and Greece are -all- attacking Victoria along with myself of course... and it is at this point that Bizmark... I dunno. I'm still scratching my head.
Bizmark decides to Capitulate to England?
WHAT!? <---- the whole reason for this entire story is WHAT THE HECK WAS HE THINKING!? He had one city, but his border was with Mali, who is also my Vassal. There wasn't a single enemy unit within 10 moves of his one lousy city and any units headed his way had to go through the very core of the Mali and Ottoman empires, and they wouldn't have had a chance. The oceans are mine - no way any naval unit gets anywhere near my good buddy ("Pleased") Bizmark. ALL of his strategic resources are being provided by me for -free-. Oil, Coal, Iron, and Aluminum. He lacked for nothing... and he stabbed me in the back.
Since I could use Mali rails it took me all of four turns to air/sea bombard his city into dust and then wipe his lousy traitorous ungrateful arse off the map, but what I really want to know is what kinda AI slashes their own throat this way?
First questionable decision: Victoria did not have units in a position to immediately threaten my cities, and had borders with two of my vassals (Mali, Egypt) both of whom combined were a match for her. WHY would she accept capitulation from a severely weakened Korea when she knows that's going to immediately get her in a war with 4 other empires? Three of those empires could easily match her militarily so all four combined were a guaranteed death sentence.
Second questionable decision: Bizmark. My power dwarfed Victoria. She shouldn't have scared him so bad but apparently she did, sohe shoots himself in the head by becoming my enemy instead of remaining my vassal?
Makes no sense.... but did make for a helluva fun morning.

So here's the setup: Huge, Terra, Marathon - started with 14 AIs plus me (Inca)
Que rushed from the word "Go" and Wiped out Russia, India, America, and France by 2000ish BC and had to stop to stabilize my economy. (That and any AIs further away were teching up beyond what my Ques could handle)
Germany had a lousy start on a penninsula and was immediately culture-locked by Mali. Lacking any turf to expand, no tech, and no resources Bizmark quickly decided life would be better as my vassal. This was around 500ish BC (I forget, long time ago now

Fast forward 1200 years or so. Power standings:
Me (about 1000pts ahead of #2)
Ottoman
England
Egypt
Greece
(Everyone else - Japan, Korea, Mali, Spain, Vikings, )
Germany
I beat the AIs to Astronomy and had the majority of North and Central America settled already. Most of South America got snatched by the Vikings and Ottomans.
Egypt had a few wars with Greece and, despite tech and power parity with England and Ottoman, negotiates a peace with Greece - and promptly decides to hop on board the Inca Train becoming my vassal somewhere around 1000AD.
Mali does the same a short time later. Alexander, in a snit realizing he can't go after Egypt or Mali because of me decides to declare on Ottoman. Mechmed who is on tech/power parity with me just kinda laughs and promptly stomps him into putty. Greece capitulates and becomes an Ottoman vassal.
By now Tokugawa is Furious with me (of course) so I decide to beat him to the punch by invading. There was absolutely no doubt he was coming for me and waiting for it would be silly - and at this point I was gunning for a Domination victory. It's about 1400AD or there-abouts.
In just a few turns I've all but eliminated Japan. Much to my surprise he had a brand new city on the very southern tip of South America that I didn't know about and, being out of position to finish that city, decide to negotiate a peace with Tokugawa so my war weariness had a chance to bleed off. By the time the 10 turns are up I'll have enough force moved down from North America to finish his piddly little size one newbie capital.
I turn my eyes towards Korea, the next weakest foe. I position my forces and invade on the same turn I wipe out Tokugawa. I crush 4 of Korea's cities on the opening turn of the war leaving only 5 left. A few short turns later I've island-hopped my way through 2 of those cities when...
Victoria has declared war on you!
Ack! Where did this come from!? I didn't want a war with Victoria - she was close to me in tech and power and all my offensive units were tied up! Gak! Turns out Korea pulled a fast one and capitulated to Victoria becoming England's Vassal .... and my enemy.
Mali, Egypt and Bizmark all being good vassals promptly declare on England. Knowing I had no offensive units and depleted defenses in my border cities (having robbed them to attack Korea) I know I probably can't stop the SOD Victoria is gonna send my way. She doesn't have gunships or tanks but she does have scads of Cavalry and cannon.

This is where having a tech lead is handy. A few fast bribes and Isabella declares on Victoria. Ragnar declares on Victoria and... *gasp* for a lousy 2k Ottoman (and Alexander as a vassal) declare on Victoria.
World War One has begun. I love this

Ottoman at this time had tech parity with -me- and I was always worried he might come after me and with Alexander as his vassal and all my offensive firepower already tied up I woulda been snuffed.
Now... I told you this entire story so I could tell you this one:

It's the late 1700s. I managed to fend off a much weaker English assault than I anticipated was coming. (Egypt and Ottoman shared a border with her and immediately mauled her border cities forcing England to go Turtle and pull all her units back to defend) I blast through all but the last remaining Korean city and lacking offensive units to take the fight to Victoria I do the next best thing - send in a squad of gunships to crash her economy and keep her attention away from my own borders.
That was last night.
This morning? This morning got even weirder

The situation: Korea has but one city left in the New World, and I own the new world, allowing me to free up all of my air and naval units to move on England. They'll take ten turns to move from Korea's last city to England's coast (no ocean route through Europe/Africa - gotta go all the way around

Anyway, in 10 turns or so I'll be hitting the beaches and leading the way will be a 40+ xp Great General Tank that is totally unstoppable. Spain, Ottoman, Egypt, Mali, Germany, Vikings, and Greece are -all- attacking Victoria along with myself of course... and it is at this point that Bizmark... I dunno. I'm still scratching my head.

Bizmark decides to Capitulate to England?
WHAT!? <---- the whole reason for this entire story is WHAT THE HECK WAS HE THINKING!? He had one city, but his border was with Mali, who is also my Vassal. There wasn't a single enemy unit within 10 moves of his one lousy city and any units headed his way had to go through the very core of the Mali and Ottoman empires, and they wouldn't have had a chance. The oceans are mine - no way any naval unit gets anywhere near my good buddy ("Pleased") Bizmark. ALL of his strategic resources are being provided by me for -free-. Oil, Coal, Iron, and Aluminum. He lacked for nothing... and he stabbed me in the back.

Since I could use Mali rails it took me all of four turns to air/sea bombard his city into dust and then wipe his lousy traitorous ungrateful arse off the map, but what I really want to know is what kinda AI slashes their own throat this way?
First questionable decision: Victoria did not have units in a position to immediately threaten my cities, and had borders with two of my vassals (Mali, Egypt) both of whom combined were a match for her. WHY would she accept capitulation from a severely weakened Korea when she knows that's going to immediately get her in a war with 4 other empires? Three of those empires could easily match her militarily so all four combined were a guaranteed death sentence.
Second questionable decision: Bizmark. My power dwarfed Victoria. She shouldn't have scared him so bad but apparently she did, sohe shoots himself in the head by becoming my enemy instead of remaining my vassal?
Makes no sense.... but did make for a helluva fun morning.
