Frank Sinatra. Sammy Davis Jr. Dean Martin. Peter Lawford. Joey Bishop.

Left to right: Sinatra, Martin, Davis, Lawford, and Bishop in 1960. (Floyd McCarty)

These five men and their influential friends were Hollywood revolutionaries, whose scandalous cavorting, steely characters, and collective ambition led the cause for progressive change in the entertainment industry during the second half of the 20th century.

The veteran of the Rat Pack was Sammy Davis Jr., whose first film role was at age seven opposite Ethel Waters in the 1933 Warner Bros. production “Rufus Jones for President,” where he played the title role.

The star was blue-eyed crooner Frank Sinatra, whose debonair style and unconventional persona made him equal parts swinging heartthrob and vilified rebel.

The jokester was Dean Martin, popularly known first for his role as one half of the comedic duo Martin and Lewis with Jerry Lewis, and later as television host of an eponymous variety program and the “roastmaster.”

Peter Lawford was the aristocrat of the group, who came to be known more as brother in law to President John Kennedy than for his film and television career.

The stalwart was Joey Bishop, who was the longest lived member of the group and the least married with a 58-year union that ended in his widowhood in 1999. He appeared on both television and film mainly in guest appearances through his 1996 retirement.

The guys performing at the Sands Hotel and Casino in Las Vegas in 1960. (Uncredited)

The strongest friendship among the five men was forged between Davis and Sinatra. Both men hailed from the New York City area on either side of the Hudson, Sinatra from Hoboken in New Jersey, and Davis from Harlem. In the years after World War II in the late 1940s, the two became friends of mutual affection while both were performing in theaters and nightclubs in Manhattan.

Sinatra and Davis’ bond was cemented when Sinatra used his clout as a popular white artist to insist on the inclusion of black Davis as part of his routine act in live performances in New York, Los Angeles, and Las Vegas, action which is credited in leading to the integration of hotels and entertainment venues where they performed together through the 1950s and early 1960s.

Audio excerpt of Sammy Davis Jr. speaking on Frank Sinatra during an interview with WCVB-TV in Boston in 1987.

The men, together, were bonded in the late 1950s by their progressive stances on issues like civil rights and integration of public accommodations, which manifested in their support for the successful 1960 presidential campaign of Lawford’s brother in law Jack.

The “Rat Pack” was originally an association of socially minded leading Hollywood entertainers formed by Humphrey Bogart, and revived in spirit by Sinatra after the actor’s 1957 death. The five performed together most notably in film in the 1960 summer blockbuster “Ocean’s 11,” and again in the 1964 comedy “Robin and the 7 Hoods,” where Peter Lawford was permanently replaced in the ensemble by Bing Crosby.

Left to right: Martin, Crosby, Davis, Sinatra, and Bishop performing at the Purple Room in Palm Springs, California, in 1964. (Uncredited)

Sinatra, Davis and Martin reunited to perform in 1988 after two decades apart for a 17-city “Together Again” concert tour. Martin pulled out of further engagements due to failing health, and was replaced on a second leg of the tour that September by showbiz darling Liza Minnelli, and the tour renamed “The Ultimate Event.”

Davis performed with Sinatra and Minnelli in the U.S. and abroad through September 1989, shortly before being diagnosed with throat cancer that he succumbed to the following May. Sinatra famously did not attend the funerals of his friends, but did so for Davis and acted as one of his pallbearers. Sinatra, “Chairman of the Board,” died eight years later.

The Rat Pack and their camaraderie was most exemplified in the relationship between Davis and Sinatra. It was a brotherhood that broke down professional and personal ethnic color barriers in Hollywood. Multitudes of performers in their wake benefit from their courage and determination to make entertainment more open, fair and inclusive.