Complex sentence: The Duke, however, did not agree to pay the amount agreed upon by his services, unleashing the wrath of the Company, which decided to declare war on the duke and meet him in battle at the Battle of Halmyros on March 15,1311.
Split into simpler sentences: The Duke, however, did not pay the amount agreed upon for their services, which unleashed the wrath of the Company. The Company decided to declare war on the duke and met him in battle at the Battle of Halmyros on March 15,1311.