It was established as a gallery of heroes to provide inspiration to the common man.

But now Scotland's National Portrait Gallery is to undergo a process of "democratisation" in a £17.6m project which will transform it into a gallery dedicated to representing the whole nation.

Yesterday, the Heritage Lottery Fund, with a preliminary "stage one" promise of more than £4.5m, and the Scottish Government, with a firm grant of £5.1m, announced the first major financial contributions towards the redevelopment, entitled Portrait of a Nation.

Along with a stronger focus on photography and Scottish art, James Holloway, director of the gallery, said the story the attraction presents will also change .

"I wouldn't say, in the past, the gallery was all about the great and the good', but it certainly was an aspirational place," Mr Holloway said. "But this is something of a democratisation - it will address the whole people of Scotland.

"There will be more landscapes, more genre pictures, more scenes of rural life - and of course, more portraits on the wall.

"I would not say the gallery is becoming more politically correct', it is just the displays will show the stories of the whole population of Scotland. Scotland is a small country where there is a great sense of kith and kin, of kinship, and now we can tell the whole complex story of the country."

The re-hang will make use of the gallery's 38,000 archival photographs, including the revolutionary calotypes of Scottish photographic pioneers Hill and Adamson, which include portraits of late 19th-century fisherman and veterans of the Crimean war.

The revamp of the much-loved Edinburgh building , which attracts more than 200,000 visitors a year, will begin in 2009 and be finished in 2011. The gallery will therefore be closed to the public for two years.

The National Galleries of Scotland will now launch a scheme to raise £7.7m from private sources, with the possibility of a public appeal at a later stage, which will increase public and gallery space by more than 50%, increase the number of works on display by a similar percentage and restore some of the buildings original Victorian features.

The project will also create a gallery for community art, a new research and study centre, as well as modernise its visitor services.

The redevelopment has been mooted for more than 10 years John Leighton, the director-general of the NGS said: "Portrait of the Nation will be a very significant development for the National Galleries of Scotland.

"Following this refurbishment we will at last be able to make effective use of one of the most outstanding buildings in Edinburgh.

"More importantly, the project will enable the wonderful collections to be presented in a coherent and understandable way, appealing to a wide range of new national and international audiences."

Linda Fabiani, the culture minister, said: "I am delighted to announce government funding of £5.1m for the redevelopment of this wonderful building which will open in 2011 as one of the most exciting galleries in Scotland.

"Our national galleries play a vital role in housing and reflecting Scotland's cultural assets as well as profiling high quality international exhibitions. This additional funding is very much a commitment to the value of our national galleries and the role they play in enriching Scotland's cultural landscape."

Colin McLean, the Heritage Lottery Fund's manager for Scotland, said: "New life will now be breathed into this beautiful historic building so that treasures that have been stored away for years can be showcased to the world."

The "Stage One Pass" from the HLF means that money has been earmarked by the Heritage Lottery Fund for the project in question. While a Stage One Pass does not guarantee funding, it is an indication of positive support, and money for the scheme is set aside.