Legendary TV personality Ed McMahon has died at the age of 86.

The Irish American, who defined the role of the television “sidekick” as Johnny Carson’s loyal right-hand-man on the “Tonight Show” for 30 years, died shortly after midnight on Tuesday at Ronald Reagan UCLA Medical Center.

At his bedside was his wife, Pam, and other family members according to his publicist, Howard Bragman.

The exact cause of death is unknown, but Bragman said that McMahon had a “multitude of health problems the last few months,” including bone cancer.

The man who coined the famous phrase “Heeeere’s Johnny!” was born Edward Leo Peter McMahon, Jr. to an Irish-American family in Detroit, Michigan on March 6, 1923.

While growing up in New York City, New Jersey and Massachusetts (and other places including Philadelphia for a very short time), Ed McMahon attended 15 different schools. His Irish Catholic father was a part-time entertainer and full-time promoter. The family was constantly on the move.

McMahon’s dad was a promoter, an entrepreneur, a traveling salesman, and a fundraiser for charities and hospitals and clubs by selling punch boards and running bingo games, which is how McMahon got his first gig calling bingo.

His mother's name was Eleanor Russell and was Pennsylvania Dutch, was raised in her grandmother's theatrical boardinghouse and was a local actress.

McMahon used to spend some of his summers with his dad's parents, Joseph F. and Katherine Fitzgerald McMahon of Lowell, Massachusetts. His grandfather was the founder of the J. F. McMahon Plumbing Company and he was a master plumber.

His grandmother was a cousin of Rose Kennedy, whose maiden name was Fitzgerald (like John Fitzgerald Kennedy).

In his grandmom's parlor, he would practice being an announcer (starting about the age of ten) and disc jockey. He would play records (“Let's Dance” by Benny Goodman was his theme) and do commercials, pitching directly from a magazine.

McMahon began working for WCAU-TV and radio in Philadelphia in 1949 for $75 a week. He was the announcer for "The Ol' Night Owl, Powers Gouraud" broadcast over WCAU Radio. He co-hosted "Home Highlights" with Jean Corbett of "Action in the Afternoon" fame. He was also the clown that opened the nationally televised "Big Top" show on CBS-TV, and hosted "Two for the Money" on Channel 10.

The Korean War and the Marine Corps took McMahon away from WCAU. He was, during World War II, a fighter pilot.

Upon his return from the service, he was back on Channel 10 hosting a morning program called "Get Happy." Ed McMahon also pioneered local late night TV as the host of "McMahon and Company," a nightly television program aired over the NBC owned and operated station, WRCV-TV (now KYW-TV and a CBS O&O), Channel 3 in Philadelphia.

From Philadelphia, McMahon went to NYC to work on an ABC-TV game show called, "Who Do You Trust" which was hosted by an up and coming comic named Johnny Carson. They were friends ever since.

Carson took over NBC's “Tonight Show” from Jack Paar in October, 1962, and McMahon acted as his sidekick on the iconic show until Carson retired in 1992.

From 1983 to 1995, McMahon hosted "Star Search" which spotlighted many, up and coming stars of the future.

McMahon is one of the few people in Hollywood to have often played himself on other TV shows. He has appeared as himself in dozens of broadcasts including “ALF,” “Just Shoot Me,” “Sabrina, the Teenage Witch,” “Suddenly Susan,” “The Simpsons,” “Who's the Boss,” “CHIPs,” “Sonny & Cher” and “What's My Line.”

The famous TV broadcaster’s medical and financial problems kept him in the headlines over the past years. It was reported in June 2008 that he was facing possible foreclosure on his Beverly Hills home. By year's end, a deal was worked out allowing him to stay in his home.

McMahon is survived by his wife, Pam, and his children Claudia, Katherine, Linda, Jeffrey and Lex.