The museum was founded on 13 April 1881, but really it began earlier - in 1827, when a group of Frisian-minded citizens formed the Provincial Friesch Genootschap, a society devoted to Frisian history, antiquities and language. For half a century they collected artifacts faster than they had anywhere to put them. The local preacher and writer Joost Hiddes Halbertsma brought in Hindelooper goods and other Frisian curiosities. In 1877 the society staged a single historical exhibition with more than fifteen hundred items on loan; it drew so many visitors it returned a profit of seventeen thousand guilders. With that money the society bought a property on the Koningstraat called the Eysinga house, and four years later the Fries Museum opened in its rooms. King William III bequeathed portraits from the stadhouder's collection. A wing went up in 1892 with a skylit gallery. The museum has been growing ever since.

She was born on 7 August 1876 in a tall narrow house on the Kelders, the daughter of a hat merchant named Adam Zelle. Her name was Margaretha Geertruida Zelle. Leeuwarden knew her then as Greetje. The world would later know her as Mata Hari, the half-invented exotic dancer of pre-war Paris, executed by French firing squad in October 1917 for espionage. The Fries Museum reclaims her. Its Mata Hari hall holds her scrapbooks, her letters, her photographs - the artifacts of a Frisian girl who built herself a new identity at the price of her life. The museum tells her story as a hometown daughter who became someone else, not as a Belle Epoque caricature.

Three objects sit at the museum's iconic heart. The first is the legendary sword of Grote Pier - Pier Gerlofs Donia, the giant Frisian rebel of the 1510s whose mercenary band, the Arumer Zwarte Hoop, fought the Habsburgs to keep Frisian freedom alive a little longer than history allowed. The sword is over two metres long; tradition says he wielded it two-handed. The second is the Hindelooper Room, an entire painted interior moved into the museum, every surface covered in the brilliant red and green folk paintwork that the fishing town of Hindeloopen produced in the eighteenth century. The third is the Great Fibula of Wijnaldum, a seventh-century gold cloak-pin found in a Frisian terp mound - one of the most spectacular pieces of early medieval goldsmithing surviving anywhere in Europe.

The museum holds the largest collection anywhere of works by Adriaen van Cronenburg, a late-sixteenth-century portraitist who recorded the Frisian gentry in cool, dark tones. Beside him hang Wigerus Vitringa's marines, Wybrand de Geest's Golden Age portraits, the floral still lifes of Eelke Jelles Eelkema, the modernist landscapes of Gerrit Benner, and the strange, dreamlike interiors of Jan Mankes, who painted in Friesland until tuberculosis killed him in 1920 at thirty. There is one outlier of international stature: Lourens Alma-Tadema, born in nearby Dronryp in 1836, who became the Victorian world's most celebrated painter of ancient Rome. His luminous Roman scenes hang here in his home province, an exhibition of his work in 2017 won the museum the Global Fine Art Award - the prize sometimes called the Museum-Oscar.

Hubert-Jan Henket's design is unmistakable from above: a sharp, angular volume of pale stone and glass anchoring the south side of the Wilhelminaplein, between the railway station and the old centre of Leeuwarden. From cruising altitude the building does not stand out - Leeuwarden is a compact provincial capital, not a metropolis - but the square it dominates is one of the few clean rectangular open spaces in the city centre, easy to pick out among the dense brickwork and the canals that loop around the old town. The Oldehove, the leaning unfinished church tower, sits a few hundred metres northwest. The Fries Museum sits at the heart of the place its collection comes from.