Complex sentence: The Japanese School, first opened as a supplementary school in 1965, and prior to the school's relocation to Acton in 1987 was located in Camden, in a building now occupied by North Bridge House School.
Split into simpler sentences: The Japanese School first opened as a supplementary school in 1965. Prior to the school's relocation to Acton in 1987 was located in Camden, in a building now occupied by North Bridge House School.