He was a trusted adviser to the shah, a former son-in-law to Iran’s last king and one of the most influential diplomats in the pro-Western government that ruled Tehran before the Islamic revolution. In Washington, where he served two stints as ambassador to the United States, he was also a suave bachelor who romanced actress Elizabeth Taylor, cultivated friendships with Secretary of State Henry A. Kissinger and Sen. Barry Goldwater, and threw lavish parties complete with conga lines, kissing games, Iranian caviar and Dom Pérignon.