Stars of US TV have paid tribute to legendary presenter Johnny Carson, who died on Sunday at the age of 79.
Johnny Carson hosted the Tonight show for more than 30 years
The former host of NBC's Tonight Show passed away after losing a battle with the respiratory disease emphysema.
Comedian Joan Rivers, talk show host Oprah Winfrey, actor Bill Cosby and Woody Allen were among those who paid tribute to the entertainer.
President George W Bush said Carson "had a profound influence on American life and entertainment".
He added: "Johnny Carson was a steady and reassuring presence in homes across America for three decades."
Carson retired from the top-rated late-night entertainment show in 1992 after 30 years as one of the most popular TV personalities in the US.
His Tonight show helped launch scores of comedy careers, including Joan Rivers, Bill Cosby, Steve Martin, Richard Pryor and George Carlin.
Rivers called Carson "truly the best straight man ever".
"He gave me my career," she said.
"You never forget when you've been working as a waitress and an office temporary and you've been working strip joints at night, and then Carson says to you, 'You're going to be a star' on the air, and it happens."
Actor and comedian Steve Martin said Carson "loved to laugh".
"His occasional touch of boyish naughtiness made America a sweet and kind place to be, and he without doubt enriched our nation," he added.
Bill Cosby said he remembered Carson as a generous performer.
"Johnny was responsible for the beginning and the rise of success for more performers than anybody," he said.
"I doubt if those numbers will ever be surpassed."
Joan Rivers said Carson launched her comedy career
California governor and former movie action hero Arnold Schwarzenegger said Carson was "an irreplaceable member of the entertainment community".
He said: "Johnny Carson shared his spirit and laughter with his family, friends and countless fans. Johnny was a great friend and always showed me profound respect."
Chevy Chase described Carson as a "real intellect with broad interests" while comedian Rosie O'Donnell said he was "the definition of class and dignity."
Daytime talk show host Oprah Winfrey called Carson "one of the greats of our time."
Actress and singer Bette Midler, who serenaded Carson during his final show in 1992, said: "I was his last guest, and it was one of the most moving experiences of my life.
"He had it all. A little bit of devil, a whole lot of angel, wit, charm, good looks, superb timing and great, great class."
Billy Crystal called Carson "the greatest talk show host of our time with the quickest mind".
"To me, he always knew exactly who he was and was always in control. He was a true giant," he added.
Woody Allen, who served as an occasional stand-in host for Carson on Tonight, said: "I liked him very much, as a comedian and as a person. I have only the most positive things to say about him. I found him to be a terrific guy."
In 2002 Carson, who often smoked during his show, was diagnose with emphysema - a disease associated with smoking.
He passed away peacefully early on Sunday morning surrounded by his family.