Bartlomiej Strobel

The Museo del Prado owns a canvas 280 centimetres high and 952 wide, nearly ten metres, that spent most of its recorded life without an author. By 1746 it hung in the Spanish royal palace of La Granja, in the room where Philip V's widow, Elisabeth Farnese, ate her meals. It shows Herod's banquet, with the severed head of John the Baptist carried in on a platter. The picture was filed vaguely as Flemish until 1970, when the Czech art historian Jaromír Neumann gave it to a Silesian painter.

His name is written two ways, both with a basis. The Prado calls him Bartholomäus Strobel the Younger, Polish writing calls him Bartłomiej Strobel. He was baptised in 1591 in Breslau, a German-speaking Habsburg city then, Wrocław in Poland now, where his father kept a painter's workshop. The arms of that city carry the head of John the Baptist on a platter, which scholars think matters for the picture. He trained in Mannerist Prague, worked for the prince-bishop of Breslau, and left Silesia in the 1630s as the Thirty Years' War closed over it. He settled in Polish Prussia, working in Gdańsk, Elbląg and Toruń, and in 1639 Władysław IV, king of Poland, made him court painter. He died in Toruń sometime after 1650.

At that width the picture cannot be taken in from one place. You walk along it, and the figures arrive a group at a time. Many have been read as portraits of the people running the war, among them the imperial commander Wallenstein with his long staff and the Dutch admiral Tromp holding a trumpet. None of those identifications is settled, and the specialist who wrote the Prado's bulletin article endorsed none of them. The museum dates the canvas to 1630-1633, others to the early 1640s, an argument turning on who is in it. One thing is plain in front of it: of all those faces, only Herod reacts to the head on the platter. The rest of the table carries on with the meal.