Hughes died at the Nepean Hospital in Penrith on Thursday of respiratory failure after a bout of pneumonia, with his son Evan by his side. The 72 year old had suffered poor health for nearly a decade, giving up his much loved cigarettes in 2008 and later, reluctantly, his even greater love, red wine.

For more than 45 years the larger-than-life dealer was a key figure on the Australian art scene, opening his first gallery in Brisbane in 1969, when contemporary art was still, in Hughes' word, something best looked at in private. He expanded into Sydney in the mid-1980s, running galleries in both cities for a short while before consolidating in the multi-storey Surry Hills building that he was canny enough to buy in 1987, when the suburb was more seedy than trendy. He ran a gallery there until Christmas 2015, when his declining health and the decision of co-owner Evan to pursue a different career path led them to close the doors.

"Dad deeply loved the work and spirit of each and every one of his artists," Evan said yesterday. "Talent and passion were all that mattered to him. More than anything he showed me the importance of artists as contributors to a civilised society. He also taught me to love museums, that they are the most important buildings in any city. The fact that my little boy loves going to the Art Gallery of NSW is the greatest gift dad gave me."

Hughes is credited with introducing Australians, including White Rabbit Gallery founder Judith Neilson, to contemporary Chinese art before it was a global phenomenon, as well as to art from Africa, Papua New Guinea and New Zealand. But his greatest commitment was to the work of living artists from his home country, nurturing a long line of them over the decades, from William Robinson, Keith Looby and Davida Allen early in their careers to Lucy Culliton, Joe Furlonger, Peter Powditch and Jun Chen.

A bon vivant in the classic sense, Hughes was equally renowned for the long lunches he hosted upstairs at his Surry Hills gallery every Thursday, to which he'd invite an eclectic mix of artists, writers, academics, politicians - anyone who might add to the conversation and could be guaranteed to stay well into the afternoon.

Hughes was painted multiple times for the Art Gallery of NSW's Archibald prize, including by Jun Chen for this year's exhibition, in which Hughes is depicted in a wheelchair, looking out through two black curtains. Hughes moved from his home upstairs at the Surry Hills gallery to the Blue Mountains earlier this year, where he surrounded himself with his favourite works by Robinson, Culliton, Furlonger and Chen. "They were the four artists who meant the most to him," said Evan.

The son of greengrocers, Hughes was only 21 when he opened his first art gallery in Brisbane, armed with "$500 and a Volkswagen". He hung the artworks on painted hessian and ran a car park on a nearby vacant lot to make ends meet. In 1982 he made a lucky strike in buying the remaining stock of legendary Sydney dealer Rudy Komon, following Komon's death, which filled his stockroom with hundreds of paintings by the likes of Arthur Boyd, Charles Blackman, Fred Williams and William Dobell.

One of his proudest moments was in 2009, when the University of Queensland awarded him an honorary doctorate reflecting his commitment to the arts. In the same year, on the 40th anniversary of his gallery, Hughes summarised his life's work.

"Being an art dealer is not about selling things. It's about somehow acquiring a bunch of things that are worth considering," he told The Australian Financial Review. "Why can this stuff keep you involved for 40 years? Because it means something. Being chic or just making money, it's not enough. In a way it's about the poetic thoughts, the notion that you were there as something quite wonderful was flowering and you happened to be holding the hose. What price on that?"

Hughes continued trading in art privately after closing his gallery, and was excited at Evan's plans to open a new space in Woollahra in January. "That will now have to open without him," said his son. Hughes is survived by Evan and his wife Kate, and their two sons, Harry and Teddy.