Complex sentence: After a year of preaching in southern England, Whitehead became known as one of the Valiant Sixty who travelled as Quaker preachers during a time of religious persecution, James Parnell and Edward Burrough being the only other teenagers counted among the sixty.
Split into simpler sentences: After a year of preaching in southern England, Whitehead became known as one of the Valiant Sixty who traveled as Quaker preachers during a time of religious persecution. Whitehead, James Parnell and Edward Burrough were the only teenagers counted among the sixty.