Sentence:  The original family who had begun to build a palace to rival Nonesuch had died out before they had put up little more than the gateway, so that the actual structure which had come down to posterity <WSD>retained</WSD> the secret magic of a promise rather than the overpowering splendour of a great architectural achievement. 
Meaning of the word marked with <WSD> tags:  To keep in possession or use.