Complex sentence: He fears that he is heading towards suicide and takes refuge at a monastery situated in the town of Martel's important symbolic victory over Islamic forces one thousand years earlier; it is also where his hero Huysmans became a lay member.
Split into simpler sentences: He fears that he is heading towards suicide, and takes refuge at a monastery situated in the town of Martel. The monastery is an important symbol of Charles Martel's victory over Islamic forces, over one thousand years earlier; it is also where his literary hero, Huysmans, became a lay member.