The Festival Aspect
Tournaments were often combined with markets and had a circus like atmosphere. Towns of any size existed largely as a center of local commerce. It was customary to hold "markets" several times a year. These were similar in appearance to modern flea markets, but much more central to the functioning of the local economy. The market crowds were just the sort of thing a tournament needed. The tournaments were run to enhance the local lords stature, and purse. A tournament brought in hordes of big spending nobles, as well as the multitudes of servants and family members nobles normally travelled with. Merchants who specialized in goods for nobles would also show up for tournaments, as would entertainers of all types, and for all tastes.
Tournaments were usually announced a year or more in advance. Often a tournament was the central part of some other celebration, such as a noble marriage, coronation, or to celebrate the birth of a son (who was probably close to a year old by the time the festivities commenced). By the 14rh century, no tournament was considered complete without an extensive array of dances, parties, and other entertainments. Performers of all sorts would show up to work the crowds, as would pick-pockets, prostitutes, and so forth..
Towns were quite enthusiastic about holding torunaments, and the larger ones would hold some of the activities within their walls, putting on jousts in a spacious square in the middle of the city. The towns, with their larger populations and array of permanent shops and amenities, also had a large enough armed militia to be used as a police force to keep the peace. Hundreds of young knights, squires and men at arms coming into contact with a lot of alcohol and each other could be a volatile mix. In addtion to the young lords, there were an even larger number of loyal servants who would cheerfully join in any brawl their masters got mixed up in. The thousands of young men of the town, and the even larger number from outlying areas along for the fun, made for a lively time. Think of it like Spring Break with no drinking laws and every adolescent armed with at least a dagger. Some of the tournament inspired brawls and riots are still remembered as part of many an ancient European city's colorful history.
The church was, in general, not enthusiastic about tournaments. Against violence in general and bawdy behavior in particular, the tournaments were too popular to be suppressed even by their most powerful clerical critics. Kings also noted an opportunity to use the "privilege" of granting the right to hold tournaments as a potential revenue source. But only the king of England was successful at this, and only partially so. Tournaments were simply too popular an entertainment for nobles and commoners alike.