boromir is mentioned in the third and last volume of the lord of the rings
he used an anglosaxon phrase that indicated a noble prince ruler or lord to refer to god however he applied this as a gloss to the latin text that he was producing and not as a clear translation of the term itself
 the lords spiritual are the archbishops of  canterbury and  york the bishops of  london  winchester and  durham and the twentyone longestserving bishops of the church of england from among the other bishops plus some female bishops of shorter service in consequence of the lords spiritual women act 2015 who are all entitled to receive writs of summons in right of their bishoprics or archbishoprics