What were actual duels in Europe like? In your typical movie, duels are shown to be long and very "clashy". I've heard that in truth, a typical duel would last under a minute, although I couldn't find any reliable sources.
Was there any real technique, or would it just be two guys bashing at each other? I have some (limited) experience with fencing, and from what I can tell, a lot of the technique goes out the window when it comes down to an actual match.
In modern sword sports, a round is very short, which seems to support the "under a minute" statement, but I feel that your average combatant would become more defense when his life was at stake, and as a consequence, duels would last longer.
Well, musketeer style dueling seen in in theaters is basically it's own separate school from sport- and historical fencing and the goal is to look interesting, as opposed to score points or killing people. My old (sport)fencing master used to teach it - it has elements of classic fencing but they are all vastly exaggerated.
We know quiet a lot about what dueling was like thanks to manuals preserved all the way back from when longsword was the weapon of choice. A famous longsword master called Hans Talhoffer(1410-1482ish) wrote that a reliable defense with the longsword was impossible and therefore one should try to be the aggressive part. This points to duels being rather short affairs.
Historical longsword fencing is practiced by the organisation ARMA. You can see a few matches here.