Originally elected as a good-government reformer, Mr. Cianci was mayor from 1975 to 1984, an era known in Providence as Buddy I, and again from 1991 to 2001, known as Buddy II. Buddy I ended when Mr. Cianci pleaded no contest to attacking his estranged wife’s alleged lover with an ashtray, lit cigarette, and a fireplace log. He was given a suspended sentence and was forced to resign. He stayed in the public eye as a radio personality, and then defied political prognosticators in his 1990 comeback, winning the mayor’s job again, this time by a few hundred votes in a three-way race decided by a recount. But Buddy II ended after Mr. Cianci was indicted in 2001 for allegedly orchestrating bribes for jobs, contracts, and contributions to his campaign fund. The FBI investigation into City Hall corruption was code-named Operation Plunder Dome. He was eventually convicted of one count of racketeering conspiracy and sent to prison, getting out in 2007. After his time away in what Mr. Cianci called a “gated community,” the former mayor returned to the radio as a talk show host — with a break for one more run for mayor in 2014, which he lost. Mr. Cianci formerly was married Sheila Bentley. They later divorced, and the only child from their marriage, Nicole Cianci, died in 2012, leaving three children.