I've never really liked the English in Medieval. Does not fit my style at all. I prefer charging in with the French, with which I had a pretty good campaign going on until the game stopped working mysteriously
With France, I chose to take my first path of conquest through the north. I started by retaking Rennes which the English had taken from me, then I took over Caen, before launching an offensive at the Rebel-controlled Dubling, then took Caernarvon, from which I had good access to both York and London, as well as a good route of reinforcements that proved quite easy to defend. I destroyed England pretty quickly by sabotaging their buildings and blockading their trade. After England, I conquered Scotland, and so had control of the British Isles. I then proceeded to ally myself with the Holy Roman Empire to protect my pretty much unguarded front from an eventual attack from Milan. I also allied with Spain to keep them from attacking me.
My next target was across the sea: Oslo. I embarked in Oslo, effectively declaring war on Denmark, which my German allies assisted me with. Didn't take long before I had conquered the Scandinavians as well. I then went into Finland and through there, Russia. Fortunately, the Russians were weak and spread thin after a war against Poland. I had little trouble taking their territories.
Meanwhile, I proceeded to reinforce my Italian front and eventually attacking Milan, then Venice, then Sicily. I now had control of entire Italy as well, save for Rome, of course. Just in time, as well, as the pope now called on a crusade, and I was the first to answer. I sailed with an army from Sicily and used it to take Jerusalem, Antioch, Damascus etc. from the Egyptians.
Then, after a lot of fun and after walking into Hungary from the previously Venetian-controlled Zagreb and conquered that, the Mongols came. It kinda went to excrement on my eastern front. I greatly underestimated the Mongols, and as a cost I lost all of my conquests in the Holy Lands, and after the Mongols plowed through Turkey, I lost all of Russia as well, and was fighting for my life at Helsinki.
Then the game stopped working.