Complex sentence: His mother and probably his father were Mennonites, members of an Anabaptist church, though it has been speculated that they may have had links with some of the more militant Anabaptist movements, such as the Batenburgers, that flourished in the Netherlands during the sixteenth century.
Split into simpler sentences: His mother and probably his father were Mennonites, members of an Anabaptist church. It has been speculated that they may have had links with some of the more militant Anabaptist movements, such as the Batenburgers, that flourished in the Netherlands during the sixteenth century.