THERE are probably only two things that a visitor knows about this 17th-century artist. First, he was a damn good portrait painter and, second, he reputedly drank like a fish. The Laughing Cavalier just about says it all, and it has been released from the Wallace Collection to take commanding place here. If that puts you in mind of the sparring partners of the Colony Club — the likes of Francis Bacon and Lucian Freud — you get the picture. To be fair to Frans Hals (1582/3-1666), he only twice entered shotgun marriages.

Writing nearly a century later, Arnold Houbraken recounts (1718-21) how an importunate stranger came to the studio door one day. He had a ship to catch for England and wanted Hals to paint his portrait. The studio assistants trawled the local hostelries and brought the artist back from his cups to paint his avid sitter.

When asked to admire it, and pay, the unknown visitor took up brush and palette, offering in jest to portray the artist. Hals realised by the way in which he handled the palette that he knew what he was doing. Benedict Trovato says that the whereabouts of neither the portrait by Hals nor that by Van Dyck is known today. Nor do we know whether Van Dyck tried to persuade Hals to come to the Stuart Court of Charles I, as Houbraken claimed. Hals seems not to have painted self-portraits, although we probably glimpse him in his 1639 group of the St George Civic Guard.

Houbraken also records how Hals remained a Catholic at heart, true to his upbringing in the Antwerp of the Spanish Netherlands. With the onset of the wars of religion, his father had moved his family to Haarlem some time after 1585, but it was not until 8 October 1655 that Hals was confirmed in the Reformed Church.

No matter how drunk he was when he was put to bed by his assistants, Hals would always mutter his Nunc Dimittis. The lads played a trick on him one night, rigging his bed up so that, when he was fast asleep, they could wake him in shock as they lifted it to the ceiling; apparently, he was never heard again to pray, “Dear Lord, bear me soon to your high heavens”.

This is a man living through the post-traumatic disorders of a convulsed age of social and religious change. The Dutch Republic emerged as a society of religious tolerance in direct contrast to the Spanish Netherlands of his native south.

The Catholic priest Jacobus Hendricksz Zuffius, formerly Archdeacon of Haarlem, might have been Hals’s first sitter (1611), while the noted linguist Johannes Hoornbeek was portrayed in 1645 shortly after being appointed Professor in Utrecht, where he taught Protestant theology. Prominent Mennonites also sat to Hals, as they did for Rembrandt. His loose brush strokes that emboldened the likes of Manet, Singer Sargent, James MacNeill Whistler, and Van Gogh, who flocked to Haarlem to see his works, knew no religious boundaries.

Seen at close hand, as I was privileged to do recently in the conservation workshops of both the Rijksmuseum and of the Frans Hals Museum, the lace cuffs and broad ruffs appear as if a cyclone has hit a forest and splayed the trees, as broad brush strokes skitter across the canvas.

Yet there are passages of closely observed detail in still-lifes such as the figured damask tablecloth set for The Banquet of the Officer of the Civic Guard of St George (1616), which, Bart Cornelis suggested to me, may be the handiwork of Passchier Lammertijn, and which, I suspect, shows Jephthah’s daughter coming out to greet her victorious father in his chariot. In a post-Reformation world, materiality had become quite as important as the individual; Hals knew how to paint both.

More than 30 years ago, the Royal Academy staged an eloquent retrospective of 86 pictures. As soon as it opened in London, it was mired in controversy. A German art historian claimed that 26 of the works were not by Hals at all. Six were denounced as copies, and the remaining 20 were studio works or those of followers “in the style”.

Computer imaging and a range of technological analyses have moved on light years since 1989/90, and a clearer picture of the artist has emerged. This exhibition has some fifty works that Cornelis has curated in a broadly chronological arrangement of portraits with sections of genre scenes. We are invited to explore more than 50 shades of black.

Although the economic bias behind commissions often constrains the artist, Hals became increasingly imaginative, suggesting surprising informality in the poses of many of his sitters. The absence of the more rigorous strictures of a Catholic, Spanish society with its strict hierarchies in the emerging Dutch Republic allowed him the opportunity to be inventive. Contemporaries recognised his virtuoso brushwork, and it, therefore, is strange that his reputation fell from favour throughout the 17th and 18th centuries, much as had Vermeer’s.

I last saw The Laughing Cavalier (1624) on its home turf, in the Wallace Collection’s brilliant 2021-22 exhibition, in which the powerful officer, wearing flamboyant attire in the French style, held court. Another dozen male portraits on the surrounding walls, arranged in a darkened space as if to suggest an all-male dining club, served only to emphasise the over-the-top outfit. Even here, he stands out.

As a distinct change from commissioned clients, the third room highlights the characterisation that Hals brought to genre pictures, which appear almost as if they are theatrical extravaganzas. Not strictly tronies, these are loosely imagined paintings.

Towards the end of the Second World War, a team of Anglo-American officers recovered the Berlin art treasures hidden by the Germans in the salt mines at Merkers. These were moved to a collection point at Wiesbaden, alongside works of art stolen by the Nazis. To the dismay of the so-called “Monuments Men”, the American government then ordered two hundred works belonging to the Gemäldegalerie (with a Manet and Daumier from the Alte Nationalgalerie) be sent to the US.

At the risk of a court martial, they refused. But Uncle Sam won, and the chosen paintings were shipped to Washington, DC, “for safe keeping”. After being hidden away, they were then touted around the country, travelling for a year to 21 cities. Seeing the photographs of the military parades, marching bands, and official receptions that greeted the paintings — Botticelli, Breughel, Dürer, Caravaggio, Giotto, and Rembrandt among them — recalls Mantegna’s Triumphs of Caesar.

Between March 1948 and March 1949, the spoils of war crisscrossed from the eastern seaboard through the midwest to Portland, San Francisco, and Los Angeles, before ending up in Toledo, Ohio.

President Truman visited the touring show twice and was invited to pick his favourites. For this particularly insensitive publicity stunt, reminiscent of how Hitler and Göring cherry-picked looted artworks for their collections at Carinhall and Linz, Truman selected Holbein’s 1532 Portrait of George Gisze, Titian’s septuagenarian Self-portrait, and Rembrandt’s Moses and the Stone Tablets (1659).

He also decided on no fewer than six paintings by Hals: a marriage portrait; a portrait of the unkempt brewer Tyman Oosdorp (1613-68), painted around the time of his second marriage in 1656; the early nursery portrait of the overdressed Catherina Hooft (1618-91) with her nurse (c.1620), alongside a Singing Boy with a Flute, trapped in spontaneous surprise, and Malle Babbe (c.1640).

The spoiled toddler of privilege, the boy with his flute, and the rough-looking street woman are among the outstanding loans here; so we can see what Truman (or his advisers) so singularly admired.

Family-group portraits and especially pendant portraits of local burghers show Hals raising the rather more matter-of-fact family record to the level of art. The Calvinist Isaac Abrahamszoon Massa appears in three paintings here. The first, Hals’s only known double portrait, is a not wholly successful marriage portrait. Although the composition is conventional, the garden and grounds in the landscape distract.

Massa might also be the man with folded arms in a three-quarter-length portrait from Chatsworth, a pose that Hals is the first to adopt to suggest informality as well as defiance. Massa was a merchant who aroused the envy of his competitors with his quasi-political involvement with Sweden and the Muscovites. In the third portrait of 1626, he stands in front of a northern pine forest, through which a woman hastens with her child in a papoose.

Massa was a good friend of Hals, acting as a witness at the baptism of one of Hals’s daughters in 1623. Another daughter of Hals later had an illegitimate child with Massa’s nephew, although the midwives tried to pin the blame on another man.

An unexpected penultimate room shows smaller works such as Willem van Heythuysen Seated in a Chair, c.1638 (Private Collection). Some were deliberately intended to be engraved, circulating widely, as Holland took over the European print market.

The last room, which also surveys how his reputation was salvaged and celebrated, brings together late works. Alongside the 1660 Portrait of a Man in a Slouch Hat is the group portraying the five Regents of the Old Men’s Almshouse. In Haarlem, it has remained where it was painted in what is now the Frans Hals Museum, paired with the five elderly women Regentesses, a painting that will be shown in Amsterdam.

Hals was in his eighties, and the magnanimity with which he paints suggests his continuing compassion for his contemporaries. At last, he seems to say, he was at ease with the world that had evolved around him.

“Frans Hals” is at the National Gallery, Trafalgar Square, London WC2, until 21 January 2024. Phone 020 7747 2885. www.nationalgallery.org.uk

It will be at the Rijksmuseum, Amsterdam, 16 February-9 June 2024; and a version of the exhibition will be at the Gemäldgalerie, Staatliche Museen zu Berlin, 12 July-3 November 2024, including works by Hals’s contemporaries and exploring his influence. www.rijksmuseum.nl; www.smb.museum