How were they able to organize such masses of people back then, giving out commands so that every single soldier knew what to do?
How were they able to march such a long distance to the middle east? Which were a few thousand kilometer if I recall right.
How did they manage logistics, fatigue and moral of each soldier?
How did they navigate?
Take a look at these answers while you're waiting:
How long did it take to march an army from western Europe to the the middle east? by /u/Porphyrius and /u/Hergrim
England to Jerusalem is an incredibly long march. How would the average participant in the First Crusade have traveled to the Levant, and how long would it take? by /u/eighthgear and /u/JudLew
How did heavily armored knights handle the heat and warm climate during the crusades? by /u/hey_dale and /u/capstaincrunch