Sentence:  She was occupied in negotiating with the ambassador of Charlemagne the conditions of the great alliance between them, whereby the crowns of the East and West were to have been united on one head, when the patrician and chancellor of the empire, Nicephorus, summoned to the emperor, burst into the palace, and at first with friendly words offered to discover all the treasures of the crown, for which he promised to make over to the <WSD>Eleutherian</WSD> palace as a widow's residence. 
Meaning of the word marked with <WSD> tags:  One of two temples on the southern slope below the Acropolis.