In May 1978, the Yawkey Estate sold the team to a partnership that included Jean Yawkey, Edward G. "Buddy" LeRoux and Haywood C. Sullivan. Mrs. Yawkey, the widow of former owner Tom Yawkey, had led the team since her husband's passing in 1976. Under the new arrangement, Mrs. Yawkey remained the club's president, while LeRoux oversaw the team's business interests and Sullivan handled baseball operations decisions as the team's general manager.
LeRoux was a Woburn, MA native who had served as the Red Sox trainer from 1966 to 1974. He had also worked for the NBA's Boston Celtics and the NHL's Boston Bruins and had amassed his wealth through a series of real estate investments. Sullivan was born in Georgia and raised in Alabama, and he had been a catcher with the Red Sox in the 1950s. After his playing career, Sullivan ascended through the management ranks before joining Yawkey and LeRoux in the 1978 partnership.
In 1981, Mrs. Yawkey established the Jean R. Yawkey trust and transferred her interests in the club to the trust. John L. Harrington, who had originally joined the team as treasurer in 1973, was appointed co-trustee by Mrs. Yawkey. While the Yawkey/LeRoux/Sullivan triumvirate continued through the middle of the decade, the club encountered turbulence when LeRoux attempted a dramatic ownership take-over in June 1983. In an incident dubbed "Coup LeRoux," the former Red Sox trainer joined team minority partners in an effort to overthrow Yawkey and Sullivan. The sides ultimately went to court and, after a prolonged legal battle, Yawkey and Sullivan prevailed.
The Jean R. Yawkey Trust eventually bought out LeRoux's share of the team in 1987, giving the Yawkey Trust two out of three general partner votes. With LeRoux gone, Mrs. Yawkey and Sullivan led the club as general partners for the next five years, with Sullivan also serving as the club's CEO/COO during a portion of the time.
In February 1992 Mrs. Yawkey passed away at the age of 83, leaving the Red Sox without a Yawkey-led ownership for the first time in nearly six decades. Into the leadership void stepped Mrs. Yawkey's trusted confidante, John Harrington.