Complex sentence: Since the school was free until 1768 it is unclear how they were taught; curiously, in this period, the headmaster, was free to keep-and did keep-cattle in a room within the School.
Split into simpler sentences: Since the school was free until 1768 it is unclear how they were taught. Curiously, in this period, the headmaster, was free to keep-and did keep-cattle in a room within the School.