So I was in bed last night watching Kingdom of Heaven and the line "Go to where the men speak Italian, then continue till they speak something else." never really clicked in my head until now. In the crusades the European Army united in one goal to fight the Muslim armies in the Holy Land, I also understand the Pope was the reason why this came about. That being said, seeing as how France and England and the Holy Roman Empire, etc. were all on the same side, how did they communicate with each other?

1. Was it common for important leaders of that time to speak multiple languages?
2. Or did everyone speak Latin as a second language and used it as the conduit in their communication?
3. Or perhaps they simply used translators like we do today.

Thanks in advance.