S. Parker Gilbert, who led Morgan Stanley when it went public in 1986 and, in retirement, steered the 2005 uprising that pressured Chief Executive Officer Philip Purcell to step down, has died. He was 81. He died on May 27 at New York Presbyterian/Weill Cornell Medical Center in Manhattan following a long illness, his son, David Gilbert, said in a telephone interview. During Gilbert’s tenure as chairman, from 1984 to 1990, Morgan Stanley’s equity rose almost 10-fold, to $2 billion, and its workforce increased to 6,800 employees from 2,600, according to the firm. Its parent, Morgan Stanley Group, issued shares in an initial public offering in March 1986, and the stock price soared 26 percent on its first trading day. With family ties to both founders of New York-based Morgan Stanley -- Henry Morgan was his godfather, Harold Stanley his stepfather -- Gilbert kept the firm “grounded in tradition at a time of great change,” the firm says in its online history. In 2005, as an advisory director, Gilbert joined seven other former Morgan Stanley executives, including former firm President Robert G. Scott, in starting a coup that deposed Purcell as chairman and CEO. Purcell had become head of Morgan Stanley by arranging its 1997 merger with his Dean Witter Discover Inc. Under his watch, almost two dozen senior bankers bolted from the firm, profit slumped and it lagged competitors. Seymour Parker Gilbert III was born on Nov. 15, 1933, one of three children. His father, S. Parker Gilbert Jr., was a U.S. Treasury Department official under presidents Woodrow Wilson, Warren Harding and Calvin Coolidge and when still in his 20s was considered “the most extraordinary man of his years in the field of public finance since Alexander Hamilton,” the New York Times wrote. Following a posting in Europe as U.S. agent general overseeing Germany’s post-World War I reparations payments, he became a partner in J.P. Morgan & Co. -- today’s JPMorgan Chase & Co. -- and was present at the 1935 meeting that created Morgan Stanley as the firm’s investment-banking spinoff. He died in 1938, at 45. Gilbert’s mother was the former Louise Todd. After being widowed, she married Stanley, the first president of Morgan Stanley. A graduate of the Hotchkiss School, in Lakeville, Connecticut, in 1952 and Yale University, in New Haven, Connecticut, in 1956, Gilbert served for three years in U.S. Army counterintelligence. In 1959, he married the former Gail Auchincloss, granddaughter of a New Jersey congressman. After stepping down in 1990, Gilbert remained a Morgan Stanley director until 1997, when he wasn’t named to the board of the merged Morgan Stanley Dean Witter. He was president of the Morgan Library & Museum in Manhattan from 1988 to 2011, and also was a trustee emeritus of the Metropolitan Museum of Art. In addition to his son, David, a novelist whose books include “& Sons” (2013), Gilbert’s survivors include his wife and their daughter, Lynn Tudor, and eldest son, S. Parker Gilbert Jr.