Complex sentence: This submission was in return for a lifelong reign over the Kłodzko region, and was influenced by the declaration of the new Polish king, Casimir III the Great, who renounced some of his claims over Silesia.
Split into simpler sentences: This submission was in return for lifelong reign over the Kłodzko region. This was influenced by the declaration of the new Polish king, Casimir III the Great, renouncing some of his claims over Silesia.