Complex sentence: War eventually broke out between the two a dispute between the Confederates of Schwyz and the Habsburg-protected Einsiedeln Abbey regarding access to pastures resulted in a Confederate raid on the abbey.
Split into simpler sentences: War eventually broke out between the two through a dispute between the Confederates of Schwyz and the Habsburg-protected Einsiedeln Abbey, regarding access to pastures. This dispute resulted in a Confederate raid on the abbey.