Complex sentence: Rise of Nelipić's power was harmonized with fall of the Šubić family's influence, with whom the Nelipić continued to have tense relations and frequent skirmishes with during the 1330s.
Split into simpler sentences: Rise of Nelipić's power was harmonized with fall of Šubić's family influence. House of Nelipić continued to have tense relations and frequent skirmishes with the Šubićs during the 1330s.