Playing Bismarck at monarch, after a long break from civ4. Had stone at my second city, so I have pyramids. Grand strategy was running SE boosted by 'mids and expansive. Berlin as GP farm/wonderspam.

Settings are aggressive AI, continents. Have 6 rival AI's on my continent, of which 3 are very aggressive; Ragnar, Kublai Khan and Monty. Managed to stay out of war until recently, when I was DOW'd by the Mongols. Had quite a few units defending my borde citys but those were smashed by the mongols tech advantage. Kublai attacked me with knights and maces when I was still defending with spears and axes. I managed to take 1 off-side city from Kublai (Phoenician) which was good, and for many turns I managed to withstand his onslaught on my borde cities (Frankfurt, Cologne), but finally, he broke through and now I cant recapture Frankfurt due to his techlead. Kublai also wont accept peace with me. Now, Im guessing I played wrong long before this war even started, so I'd like some hints as to what mistakes I might have done earlier in the game.
One thing that bothers me is Im behind in tech compared to all other civs on the continent. The other civs has warred frequently between themselves, while I have stayed out of conflict. Shouldnt I have strong tech with SE+mids as Bismarck?

You are not running a "specialists economy". I counted 4 specialists, that's not even close to good enough.

However the reason you fall behind is simple: You are working way to many unimproved tiles. Chop those trees and build some useful improvements.

I suggest that you post screenshots as well (especially during the day). Without being able to look at your save, if everyone is fighting everyone else, then you shouldn't be that far behind tech-wise. Were you tech trading? Were you developing your land properly? Did you have really crappy land? Were you exclusively wonder-spamming and neglecting your defenses (these are warmongers on aggressive AI's after all)?

Usually when the AI's are fighting amonst themselves, tech progress tends to grind at a really slow pace.

Bad tech path. You're researching guilds, which is not very useful and all the AIs have anyway (so you can't trade it). There are quite a few techs like that which the AIs all grab every game and should be ignored while you get stuff you can trade for them =)

Begged 80 gold from Saladin & traded silk for wheat
Switched research to Civil Service
Begged 170 gold from Monty

Started putting workers to use. Wanted more but couldn't afford. Put double hill-defense upgrades on a longbowman, dumped him on a hill and let Kublai suicide 2 units against him... taking Frankfurt was easy.

Popped a Golden Age out of a Great Prophet. went into Theocracy, Vassalage, and Buddhism. Started building a great monestary in Munich to spread religion..

Not enough workers!!@! You've got cities working forest hills with no mines on them! Saving forests shouldn't mean utterly decimating the gigantic advantages of chopping and mining forest hills.. Basically, rather than giving you a massive advantage your specialists are just giving your hillbilly empire the bare minimum of life support.

holy crap wonders D:!

This is annoyingly difficult due to war + having to rebuild empire from nothing at the same time =/

Interesting game.

Okay capital as a national park I dont really like. You have all that forest to chop wonders early on or build units to knock out a nearby AI. Why cripple your capital till late game??

Capital has national epic. No specialists and its struggling for food as most of the tiles have forest. Most of which are hiding grassland. Either irrigate for specialists or cottage them all. Irrigated grassland would help get 3-4+ specialists and almost double your great people points. The great library would help here too with 2 free specialists!!

A production capital with wonders would also work as a GP farm. A decent GP farm could be getting +100 great people points a turn. 240+ is not unheard of.

On the worker front. You really need 1.5 to each city early on. Even 2-1 with first 1-2 cities.

You had no cottages in your entire empire!! Cottages over time create commerce which can be used for science or gold pending on your tax slider. You cant build cottages if the grasslands are covered in forest!!! Chop chop!!! You wont get far on this game without using cottages!! 6-7 cottages in Berlin would of had a huge boost on science.

Specialist. You had about 2 specialists. If you are not using cottages you need specialists to generate science and gold. The pyramids and representation with lots of science specialists would help double your current 135 science beakers a turn.

I have no idea why you founded Munich your third city so far south. Cities further away from your capital have higher costs!! I dont quite get your city placements either. Some overlap is fine but the capital could of used most of its land on its own.

Managed to get Education fast enough for some nice tech trading. Still was far enough behind with universities, cottages, and Oxford it took awhile to totally catch up. Cottages coming online now and I have #1 GDP and almost double #2 production..

mostly due to being the only player with steel, steam power, and railroads.

Isabella somehow managed to survive MULTIPLE wars with Ragnar, Kublai, and Montezuma. I took some of Kublai's cities and she vassaled him. Despite the fact I beat her nightly and did her sister twice she still loves me (+8 buddhism, +4 civics!)

Got a Great Engineer.. mining inc coming in three turns. Moving two big outdated armies over to see Saladin.. I want all his wonders, like everyone else he has riflemen. I think I'll just swamp him with cannons.

http://img215.imageshack.us/img215/140/empirebismark.th.jpg (http://img215.imageshack.us/i/empirebismark.jpg/)

(Note that the army on the left side of the screen is different from the one on the bottom).

1900 AD and everything is lovely. Clear tech lead, several minerals popped giving Mining Inc. 6 in all cities (I'm used to 12 or more, but you take what you can get.)

My Wall Street city has 7 merchants and 4 engineers =) I took Mound City and Tabriz (riverside gems, beautiful cities) culturally. Fed Isabella about 20-30 infantry and some Panzers, since Ragnar and his vassal gang were finally starting to overpower her. Don't know how she stood up to him all friggin' game but the he's utterly screwed now due to

A. losing two decent cities to cultural revolution;
B. me about to declare war
C. isabella is currently raping him with panzers

Amusingly enough:http://img258.imageshack.us/img258/9369/panzertime.th.jpg (http://img258.imageshack.us/i/panzertime.jpg/)

Note the MFG..