The St Trinian's Collection - FClaw

St Trinian's is a film series based on a series of cartoons by Ronald Searle (who also was responsible for the molesworth books and Dick Deadeye, or Duty Done). The films are set in a disreputable girls' school where the only rule is that there are no rules. The girls themselves are teen and pre-teen horrors who are not above using their feminine wiles to get away with murder. The teachers? They're teaching the girls how to get away with crime in foreign countries and mixing drinks. The headmistress, Miss Fritton, has no interest in maintaining any form of order. And there's a local spiv, Flash Harry, who makes money from whatever schemes the girls cook up (usually).
The original film series consists of:

The Belles of St. Trinian's (1954): The decrepit school is desperately in need of some money, so the headmistress allows the girls to place bets on a horserace. Things get out of hand when the classes place bets on rival horses.

Blue Murder at St. Trinian's (1957): Flash Harry (George Cole here) sets up a marriage agency, resulting in a prince wanting to meet the girls. Problems arise when the jewel-thief father of one of the girls decides to hide out at the school.

The Pure Hell of St. Trinian's (1960): The girls are kidnapped and forced to defend themselves against the sons of an Arabian Emir, who want them as their wives.

The Great St. Trinian's Train Robbery (1966): The school takes over a mansion in which thieves have hidden money.