They were farmers, day labourers, small-town craftsmen and their families' menfolk, from villages across Thuringia and the Saxon estates. What they wanted had been printed that spring in the Twelve Articles and was circulating across Germany in cheap editions: the right of a parish to choose its own pastor, an end to serfdom, access to the woods and waters that lords had enclosed, an end to the death duty that took a household's best animal when the head of the family died. It was not a utopian document. It was a list of grievances that had accumulated for generations.

Frankenhausen went over on 29 April 1525. Much of the citizenry joined, took the town hall, and stormed the castle of the Counts of Schwarzburg. Insurgents kept arriving through early May, camping in the fields and pastures. Thomas Müntzer reached the town on 11 May with three hundred fighters from Mühlhausen, bringing a theology in which the poor were God's chosen instrument and the princes' hour had come.

The two armies were not comparable. Around eight thousand peasants faced at least six thousand professional soldiers under Landgrave Philip I of Hesse and his father-in-law George, Duke of Saxony — Landsknecht mercenaries with cavalry and field artillery. The peasants had polearms, farm implements pressed into service, a scattering of breastplates, and the handguns some owned from service in local militia bands.

They were not helpless. On 14 May they drove off a scouting party and its reinforcements, and then made the disciplined choice not to chase it. Late that day they pulled back into a wagon fort on the hill above the town, the standard defence of the period, and someone — it is not known who — opened a truce. The pause was fatal. It gave the princes the hours they needed to link up with George's column coming from the east and close a ring around the hill instead of besieging the town.

Around midday it became clear that the peasants would not hand Müntzer over, and the truce ended. The artillery opened first, into a mass of people packed behind a barricade of carts, and then the horse and foot went in. The formation broke almost at once, and what followed was not a battle but a pursuit — down off the hill, through the streets of Frankenhausen, with mercenaries cutting down people who were running.

At least six thousand of them were killed. On the other side, six men died. A place on the slope is still called the Blutrinne, the blood channel, where a group turned and tried to make a stand. Six hundred were taken prisoner; three hundred of those were executed the following day. The villages that had sent men were then assessed reparations that ran to many times the damage the rising had actually done, so the households that had lost fathers and sons paid for the privilege.

Müntzer was found in the town, hiding. He was handed to Count Ernst von Mansfeld and taken to the moated castle at Heldrungen, where he was tortured, and on 27 May 1525 he was executed in the princes' field camp near Mühlhausen. He was somewhere in his mid-thirties.

He has been argued over ever since, which is what happens to a man who left sermons and led an army and lost. Luther, who had encouraged the princes to strike hard, wanted him remembered as a fanatic. Later revolutionaries wanted him remembered as a prophet of the coming order. Both readings need him to be larger than life, and both quietly do the same thing to the people who followed him: turn them into a crowd, a movement, a casualty figure. They were none of those things until the fifteenth of May made them so.

The East German state commissioned Werner Tübke to paint the battle on the hill where it happened, and he began work in 1976. The leadership wanted something heroic and monumental — Müntzer as revolutionary forebear, the peasants as the first act of a story ending in the GDR itself.

Tübke worked until 1987 with fifteen assisting artists and delivered something else entirely: a canvas 123 metres around and 14 metres high, 1,722 square metres, with more than three thousand individual figures and no simple message anywhere in it. He painted in a dense, jewel-toned late-Gothic manner that had nothing to do with socialist realism, set the battle inside a whole disintegrating world of Reformation Germany, and put Müntzer at the centre as a tired and broken man beside a fallen banner. The purpose-built rotunda opened on 14 September 1989, weeks before the state that ordered it began to come apart. Visitors stand in the middle and turn slowly, looking for a face.