Barbarossa's March

Try doing it on easiest if you already aren't. IF that dosen't work try moving your town somewhere else to build a army. It worked for me.

Try it on difficulty level easy

There is one other option you could use, cheat, put the words just like this: "i are winner"
It has to be just like that, otherwise it wont work

I played the game on the hardest mode. It seems the best way to win the game is to start preserving your army from the very beginning.
1) onagers: onagers are good for clearing and making paths through woodlands. Use your onagers at the beginning of the game to clear a narrow passable path through the forest adjacent to base camp. I.e. The starting point.
2) once done start to move your forces into the clearing. BE MINDFUL NOT TO DISTURB THE BYZANTINE NAVY IN ANYWAY!! You risk losing galleons. And keep your forces away from the shoreline, the saracen navy is lurking nearby.
3) organization of troops for an ambush: this is how you separate your forces to make for an effective ambush. Pikemen separate, archers separate and teutonic knights separate. Form them into a V covering the opening created by your onagers. Time to trigger the saracen ambush and possible get four mamelukes and a ship..
4) with your scouts move to the river( not the sea of marmara). There is a lone saracen galleon, convert it. Keep it away for the sea wall.
5) Triggering the saracen ambush: take your paladins and rush into the abandoned house. That is enough to trigger the ambush. They will be preoccupied beating up the house and the farm. After that you can lure one mameluke at a time and have them converted by your monks.
6) invasion of constantinople: again run in front of the gates and casue the cataphracts to follow you into your previous ambush set up. This is real effective. With the combination of the halberds , teutonic knights and archers you cannot go wrong, save your palading fro the three onagers that come from the byzantine side. Once you decimated the army, it's time to take down the towers and enter the city and get yourself a navy. You need to position at least one trooper in front of the hagia sophia. This will trigger the saracen ground troops to attack you with camel laden troops supported by onagers. These will be the only troops on the ground for the saracen navy. The road to galipolli will be free of encumberances. All you need to do is take out the castle and tower you will encounter on the road. Galipolli is free. Take out the saracen dock on your side. There is another on the other side.
7) surprise!: you are going to find a shipwrecked crew of french throwing axe men and a trebuchet, use this to take out the bombard protecting the other saracen dock. Take that dock out in turn. You have effectively stemmed the production of ships. Use your galleons to take out the rest of the navy.
8) landing: you should take a very slow approach to landing. Do not be rash and use the geograpghy to your advantage. The northern most area has a small patch of beach where you can land your onagers and start clearing the forest paths. This will land you right in the rear of a selijuk patrol. Create havoc from the rear and land in larger patch of beach immediately below where you landed your onagers but way above the danger zone ( the safe landing directly across from astern tip of the walls of constatntinople. Rest your army as well as yourself.
9) use your galleons to weaken the danger beachforce, be careful, those onagrs and bombards are dangerousely efficient, keep moving and try to hit multiple targets, do not be a sitting duck. Once you feel that you are sufficently happy with the damage you caused. Land and establish a beach head.
10) after this point it is all about scouting ahead and taking things down guerilla style. Advance slowly and patiently. Protect your siege weapons and march ahead!