Complex sentence: Reynolds asked that his master, Silken Thomas, be absolved of the murder of Archbishop Alen, who he argued had supported the heretical policy of the English crown, and had plotted murder against his masters, the Earls of Kildare.
Split into simpler sentences: Reynolds asked that his master, Silken Thomas, be absolved of the murder of Archbishop Alen. The Archbishop, he argued, supported the heretical policy of the English crown, and had plotted against the Earls of Kildare.