Just won with Geoffrey Longsword. Unfortunately, it appears i forgot how to joust.
I remember it took me a while.
Tips:
#1: don't be afraid to ask Robin for help early. When you need the men and are short on money, they can do wonders. Later, when you're richer, you can usually afford what you need anyway.
#2: Knights are cool, but soldiers win battles. 5:1 soldiers to knights is the lowest ratio you want. 7-8:1 is a bit better, though this can vary.
#3: Play to your strengths. Great leaders fight battles better (At least supposedly). Great Swordsmen should raid (Potentialy lots of cash 70+ gold) and rescue damsels in distress (Good for morale, can potentialy raise a quality). Great Jousters should joust (Fame can help raise qualitys, and improve morale, jousting for land is a great way to win 3 pieces of land in one turn with no fighting.
#4 Very early, put everything in your campaign army. You get more soldiers for conqouring uncontrolled land, and if no one can threaten your castle, what good are they doing there? Same think later with your home castle if it's surrounded by your own land.
#5 Practice. Swordsmanship isn't too tricky, but if you're good at it, you can get another character strength instead. Same with Jousting.