To say the gallery, opened in 1864, has had a renaissance of its own is no understatement. But in the late Eighties, with its leaking roof falling in and major works suffering damage, it was a depressing place. Slack security prompted one art-lover to purloin a small French oil and post it back to the gallery as a protest. With few touring exhibitions and a hotch-potch of discordant decor styles, the director of another state gallery called it "a national disgrace".
The renewal, and the relish with which the new management under Raymond Keaveney, director since 1989, have gone about it, followed a changed attitude by the Irish state to its cultural crown jewels. The controversial Charles Haughey, whose third period as Taoiseach from 1987 to 1992 saw numerous Mitterrand-style moves in publicly owned arts, was crucial, accommodating arguments that tourism and employment would benefit from heritage investment.
This judgement has since been vindicated with Dublin's National Gallery now achieving 1.1 million visitors annually, a figure comparing favourably, Keaveney points out, with the Victoria & Albert Museum in London and the Uffizi in Florence.
After four years and IRpounds 9m (pounds 9.4m), a radical expansion and facelift has allowed the number of works on show to be doubled and every room to be refurbished. One might quibble with the odd choice among the 36 rooms, but the replacing of chilly backgrounds with more enticing colour schemes has been long overdue.
For years, ground-floor walls were, to put it politely, afflicted with a shrieking shade of green, recalling Billy Connolly jokes about gastric turmoil on the morning after the night before. Less strident backgrounds, from a gentle salmon-red to a faint blue, now allow restored Old Masters' rich hues to emerge unchallenged. The new North wing's smaller intimate spaces for English and "visiting artists" will be a pleasant surprise for those used to seeing works lost in vast prairie-like spaces.
The principal gallery staff - Keaveney, the assistant director, Andrew O'Connor, and senior conservator, Sergio Benedetti (the baroque Maigret who discovered the Dublin Caravaggio three years ago) - make up an energetic but informal group. Their decor choice was collaborative, "but the final decision was Sergio's," says Keaveney.
The project is immense, but it is subtlety, not scale, that makes it work. The delicacy of touch hits home in the way existing features, such as intricate carved-wood door-frames by Carlo Cambi of Siena, previously overshadowed, have been enhanced by new backgrounds to become handsome adornments against muted mushroom and pistachio shades.
A special multi-media viewing room with a rapid retrieval system will allow scholars and others easy access for the first time to items in storage from a total collection of 13,000 works.
The job began, however, with the basic fabric of the building: heating, lighting, ventilation have all been upgraded, with London Tube-sized lifts carrying 60, and wheelchair-friendly ramps aiding movement.
Another Irpounds 14m (pounds 14.6m) will complete the final stage, to be finished in the year 2000, when the gallery will have another 50,000 square feet on recently acquired adjacent land - 40 per cent more than at present.
A key feature there will be a gallery-within-a-gallery, the Jack B Yeats Museum, featuring works by the artist brother of the poet WB Yeats, including a major family bequest of sketchbooks, studio contents, a library and family memorabilia. "While the name is most associated abroad with the writer, the Yeats family were ironically more pre-occupied with the visual arts," Keaveney points out.
Other improvements include extra space for touring exhibitions, an auditorium and an expanded bookshop. To proceed, IRpounds 6m (pounds 6.2m) must be raised by the gallery itself this year, causing intermittent panic attacks for Keaveney. To encourage the generous and wealthy, Mr Haughey has come out of retirement to head an ambitious international fund-raising drive.
This headache is temporarily forgotten as Keaveney proudly shows off the pride of the collection. In upstairs glass-roofed rooms, which earlier escaped the green plague, lies the real wealth of the collection: a newly assembled treasure trove of baroque gems, many unseen in years. Extra space has allowed a wealth of fine but little-known Italian and Spanish works to be brought out from storage alongside recent purchases.
"We've made logical connections. It's not just one school in one room," explains Keaveney. "We decided to create special displays of an artist and his followers, for example with Caravaggio and Rembrandt." The effect is to develop what was once a discursive cruise through the centuries into an enlightening tour of developing European styles.
n The National Gallery of Ireland, Dublin, opens to the public on Saturday (00353 1661 5133)
n The final extract from Andrew Graham-Dixon's 'A History of British Art' will be published in the Independent next Tuesday
Ten to see at Ireland's National Gallery
This selection includes new acquisitions, and several paintings not seen in recent years.
1) Triple portrait by Santi di Tito. The only old master bought recently (1994) by the gallery. From the counter-Reformation movement in the late 16th century, its early realism is unnerving. "The artist was determined to simplify paintings so they could be understood by the majority of ordinary people," says Raymond Keaveney.
2) Newly-acquired arresting self-portrait by Leo Whelan (right) highlights the then new-found confidence among post-Independence artists such as Sean Keating, projecting distinctly Irish images.
3) Long absent from display, Sir Joshua Reynolds's garishly ugly faces in Parody of the School of Athens paves the way for James Gillray's Spitting Image era of caricature.
4) With serene but rueful gaze, Goya's actress friend Dona Antonia Zarate echoes the ambiguous smile of the Mona Lisa. The Goya is especially prized - missing for eight years after its 1986 theft from the Beit collection by the eccentric Dublin gangster Martin "The General" Cahill, it was hidden initially in an underground bunker in the Dublin mountains. It re-appeared in Istanbul, returning to the gallery a month after Cahill's assassination by the IRA in 1994. Remarkably, given this history, it is in superb condition.
5) Shepherd finding the Infant Cyrus by Castiglione (1616-1670) exemplifies the Italian classical technique on a giant scale in lighting, landscape and animated figures. Delicately brushed clothing anticipates later dreamy works of Alma-Tadema and Leighton.
6) Retrieved from storage, Scenes from the Life of St Augustine is a vivid technicolour strip-cartoon by the unnamed "Master of the Silver", packed with intriguing detail. Is the procession of priests at the bedside hoping for more than just blessings?
7) In Orazio Gentileschi's David and Goliath (right), a sweeping blade- wielding hand in the foreground confirms a master's technique. The violent movement bursts from the canvas as if caught by a photographer.
8) One of several Arab scenes, Gustave Guillaumet's Women in an Eastern Courtyard captures a relaxed warmth with a feeling for light and exotic colour.
9) Charles Emile Jacques' Shepherdess and Sheep with Dog Near Wood applies light on a flock of sheep in a boldly naturalistic pastoral scene.
10) The recently-acquired Jack B Yeats That Grand Conversation was under the Rose has a title drawn from a political ballad of the Napoleonic period. Its rose symbolism carries a distinct nationalistic message.