First some undergraduates got drunk over in a tavern, and then they didn't pay, and so the townspeople beat them up.  That was Shrove Tuesday.  Fair enough.  On Ash Wednesday, the beginning of Lent, when they were supposed to be repenting and thinking about their sinful lives, the students got some buddies together and went and trashed the pub, beat up the taverner, and looted and trashed the nearby businesses. But the townspeople couldn't do anything about it, cause the local law couldn't do anything to the students, and the church wouldn't. So the townspeople went to the Queen, who said the students should be punished. Which the town guards interpreted as a command to kill whatever random students they came across. Which they then did.  And then the whole university got very mad and disbanded and everybody left town, and the townspeople had lots fewer customers than they had earlier. Well!  That was Lent, 1229, Paris.  A very holy time, as you can see. Oh, and by the way. The strike wasn't the crime. All that Lenten hoohah was.