When: 1618

The castle fire of 1618

Fire took the Renaissance castle, and what replaced it gave Weimar a Baroque residence and, eventually, Bach's chapel.

In 1618 fire destroyed the Weimar castle — the Renaissance building called Hornstein that had itself risen after the town fire of 1424. Rebuilding began the following year, and the palace that came out of it carried a new name and a new century's shape: the Wilhelmsburg, after Duke Wilhelm IV.

The second castle to burn

This is a site with a habit. A medieval moated castle stood here first; after the town fire of 1424 the complex was rebuilt as the Renaissance castle Hornstein; in 1618 that burned in turn.^[1] The one thing every version of the building has in common is that Weimar rebuilt it — a small duchy that could not afford to be without a residence, three times over.

What replaced it

From 1619 the site became a Baroque three-winged palace open to the south, and it took the name of the duke who drove the work: the Wilhelmsburg.^[1] Wilhelm IV supervised the building himself and had his interests put into it — mechanical devices, an astronomical observatory, a good organ in the chapel.^[2] The chapel was finished in 1630.^[3]

Why the year is a boundary

The Reformation century ends here, and the Baroque one begins. It is a building fact rather than a literary one, and that is the point: the century of Luther's sermons and Cranach's altar closes when the house the Ernestine court had lived in since 1552 burns, and the next century is spent in a different building, with a chapel in it that a court organist would later make famous.

Sources

Stadtschloss Weimar — Geschichte — Klassik Stiftung Weimar, retrieved 29 August 2026
Wilhelm IV., Herzog von Sachsen-Weimar — Allgemeine Deutsche Biographie, retrieved 29 August 2026
Wilhelmsburg — Bach-Archiv Leipzig, retrieved 29 August 2026