Complex sentence: The local dynasties saw the presidencies as intrusions into their sphere of influence, and into their traditional violent competition over the balance of power which had seen the Butlers and Fitzgeralds fight a pitched battle against each other at Affane in Waterford in 1565.
Split into simpler sentences: The local dynasties saw the presidencies as intrusions into their sphere of influence, and into their traditional violent competition over the balance of power. This had seen the Butlers and Fitzgeralds fight a pitched battle against each other at Affane in Waterford in 1565.