Complex sentence: At the time of founding it was reported that there were approximately 50 Zoroastrians in England who were mainly students but Parsis have been a presence in the United Kingdom long before the foundation of the ZTFE; the first arrival being Nowroji Rustom Maneck Sett in 1724.
Split into simpler sentences: At the time of its founding, it was reported that there were approximately 50 Zoroastrians present in England who were mainly students. Zoroastrians have however been present in the United Kingdom long before the foundation of the ZTFE; the first known Parsi arrival being Nowroji Rustom Maneck Sett in 1724.