Complex sentence: By 1568-69 Crowley had resigned or been stripped of all his preferements and returned to the printing trade, though that was his immediate reaction in 1566 as well when he leed the nonconformists in a bout of literary warfare.
Split into simpler sentences: By 1568-69 Crowley had resigned or had been stripped of all his preferements. He returned to the printing trade, although that had been his immediate reaction in 1566 when he led the nonconformists in a bout of literary warfare.