In many instances, he was the first Australian art gallery professional to put Australia on the international art map as a place that was serious about collecting art of the highest calibre and as a place that possessed a vision for the creation of a national art gallery that would be on a par with major art collections in the world.

Mollison, who died on January 19 aged 88, was born in Wonthaggi in rural Victoria. He trained as a secondary school teacher before serving as an education officer at the National Gallery of Victoria and then briefly running a commercial art gallery in Melbourne and between 1967 and 1968 he was the director of the Ballarat Art Gallery.

He came to Canberra in 1969, as the executive officer for the Commonwealth Art Advisory Board and as the exhibitions officer in the Commonwealth Prime Minister's Department.

Two years later, his position had morphed into that of the acting director of the fledgling Australian National Gallery and by 1977 Mollison was appointed as the director of the gallery, a post that he retained until 1989, when he returned to his beloved Melbourne. From 1990 to 1995 he served as the director of the National Gallery of Victoria.

What is Mollison's legacy? It is huge, multifaceted and not what most people imagine.

Mollison spearheaded the creation of the Australian National Gallery (the name was changed by a subsequent director in 1992, possibly a retrograde step that detracts from the uniqueness of the institution) and he shaped much of its collection.

Although in the popular imagination Mollison was remembered for a number of spectacular and relatively expensive acquisitions of American art, including Jackson Pollock's Blue Poles, 1952, Willem de Kooning's Woman V, 1952-53 and Helen Frankenthaler's Other generations, 1957, these were not the most important or the most expensive acquisitions.

But in the toxic political climate of the Whitlam years they were the easiest targets to attack by philistine politicians and the ignorant gutter press. Subsequently, they have been seen as a great coup and have multiplied in value more than 300-fold, and gave Australia an immediate presence in the international art market.

On one occasion, Mollison quietly told me, these were far from his "favourite works", but he realised that they were very significant and the time was right for their acquisition as soon they would be completely out of range for any Australian public art collection.

Also in these early halcyon years, hugely significant "masterpieces" including the Lake Sentani figures and the Ambum Stone, were acquired for record prices, as well as Giambattista Tiepolo's Marriage allegory ceiling oil painting, which has been variously dated from the 1720s to the 1750s, Giovanni di Paolo's Crucifixion, possibly dating to 1444 and an impressive self-portrait attributed to Peter Paul Rubens of 1623.

In 1974, Mollison was able to acquire Kazimir Malevich's House under construction, c.1915-16. Despite the million-dollar price tag for this non-figurative work, its acquisition drew little negative comment in the press. By 1979, Mollison purchased Claude Monet's Grainstacks, midday, 1890.

Constantin Brancusi's Birds in space, 1931-36, and Amedeo Modigliani's Standing nude, c.1912, were purchased and were the two most significant acquisitions of modernist sculpture to be made under Mollison. They remain amongst the most important works of international sculpture in Australia. In 1980 he acquired Louise Bourgeois's brilliant C.O.Y.T.E, 1941-48 from the artist.

Although popular rhetoric of the time was cased in terms of "masterpieces", Mollison lay the foundations for the major signature collections for which the gallery was to be known in the future. These included 600 works from the Ken Tyler print workshops on the West Coast of America that he acquired in 1973 that lay the foundation for the fabulous international graphics collection.

He also bought a pristine copy of Picasso's Vollard suite in 1984, that has served as the subject of numerous blockbuster exhibitions as well as the extensive collection of Ballets Russes costumes and stage designs and a huge collection of Russian graphics, photomontage, photography and futurist art.

The gallery under Mollison built up one of the most significant collections of Russian avant-garde revolutionary art to be found anywhere outside of Russia.

Simultaneously, Mollison established major heritage collections of Australian printmaking (he himself was an amateur printmaker), Australian photography, applied arts as well as Australian painting and sculpture. Not only did he collect well and was nearly always ahead of art market fashions, but he also collected and invested in staff and in a professional library for the gallery.

It was under his stewardship that Sunday Reed gave the gallery Sidney Nolan's Kelly series, Arthur Boyd gifted a huge number of his works and the gallery acquired the Aboriginal Memorial.

Mollison sought out and appointed the best curators in the trade and appointed young promising graduates that they could train and who would form the backbone of the Australian gallery system.

Within a very short number of years, Mollison established a new benchmark in art gallery professionalism in Australia in curatorial practice and in the handling of artwork, which, within a decade, revolutionised much of the Australian art scene.

He was a man driven by a vision, a workaholic and one who possessed an infectious enthusiasm for art that affected many of those who surrounded him. Like a librarian who loves books, Mollison was an art director who loved art and by the time the gallery opened to the public in 1982, it had a collection approaching 50,000 art objects, while by 1998, this had jumped to over 90,000 art works.

The primary focus was a comprehensive collection of Australian art, but this was complemented by collections of Asian and Oceanic art, as art of the surrounding regions, as well as an extensive selection of international modern and contemporary art.

All of these areas were collected across many mediums including painting, sculpture, prints, drawings, decorative arts, fashion, theatre arts, photography and film. Surrounding this core was a small number of 'masterpieces' not constrained by date, medium or tradition but supreme examples of internationally significant art.

Although he occupied some of the most public art positions in this country and became the most recognisable art professional in Australia, Mollison was also a very private individual, passionate about art and artists and even after his retirement from public life, he quietly encouraged a number of artists whose work he valued.

It was rare to see him not enthused by some artist whose work he had recently encountered or a book that he had just read.

He had spent many decades working on his major project - his life's work - a comprehensive catalogue raisonné of the prints of Fred Williams, an artist who was a close friend and on whose work he had already published a major monograph and had curated a huge exhibition.

Mollison was a unique individual who possessed a great eye, charisma, endless energy and a passionate belief that Australian art, at its best, stands up well in any international company.

The creation of the National Gallery in Canberra may be his most distinctive and visible contribution to Australian art, but his influence went much further and had a profound impact on the whole Australian public art gallery scene and the way in which many Australians see art today.