Richard Beattie, a mergers lawyer who helped pioneer private equity takeovers — work that was immortalized in the much-lauded book “Barbarians at the Gate” — and who served in Washington and New York City government, died on Friday at his home in Manhattan. He was 86. Beattie was Chairman of Simpson Thacher & Bartlett LLP, a law firm, a position he held since May 2004. Mr. Beattie has been a partner of Simpson Thacher & Bartlett LLP since 1977 and had served as Chairman of the Executive Committee of that firm from 1991 to 2004. Mr. Beattie is an expert in corporate governance issues, serving as counsel to numerous boards and non-management directors. Mr. Beattie also had a distinguished record of public service, including serving as General Counsel of the Department of Health, Education and Welfare during President Carter's administration and as a Senior Advisor to the Secretary of State for Reorganization Issues in 1997 during President Clinton's administration. From 1995 to 1997, Mr. Beattie served as President Clinton's Emissary for Cyprus. Mr. Beattie was also a director of Heidrick & Struggles International, Inc. In addition to Lisa Beattie Frelinghuysen, he is survived by his wife; his daughter Nina Beattie; his younger sister, Evelyn Lewis; and six grandchildren.