Step inside Gustav Vasa's red-brick castle on Lake Mälaren

Bo Jonsson Grip built the first stronghold on this islet in the 1370s, giving Gripsholm its name. In 1526, having founded the House of Vasa, King Gustav I dissolved the Carthusian monastery then on the site, and in 1537 began raising a fortified royal castle in its place, designed by Henrik von Cöllen.

The castle's four round towers, thick enough to hide spiral stairs and storerooms inside their own walls, were built as much for defence as for display — a working fortress for a new dynasty that had just fought its way to the Swedish throne and had every reason to make that power visible in brick and stone.

Between 1563 and 1567, King Erik XIV imprisoned his own half-brother, Duke John, and John's wife, the Polish princess Catherine Jagiellon, inside Gripsholm on suspicion of treason. Their son, born at the castle in 1566, later became King Sigismund of both Poland and Sweden.

The story turns on itself: barely four years after John's release, Erik XIV was deposed and, from 1571 to 1573, held prisoner in the same castle where he had once locked up his own brother — the jailer become the prisoner, within the very same red-brick walls he had once ruled from as king, a reversal few royal houses anywhere have matched.

Duke Karl — Gustav Vasa's youngest son and the future King Karl IX — left Gripsholm its single most intact interior. His chamber, fitted out in the 1570s, still holds its original furniture from that decade, and the painted ceiling frescoes date to 1573.

Because the fittings are too fragile for foot traffic, visitors view Duke Karl's chamber through a glass screen rather than walking inside. What you see is not a reconstruction but the room itself, essentially unchanged for four hundred and fifty years — furniture, frescoes and all, exactly as the future king left it when he moved on to a throne rather than a chamber.

Gustav Vasa began collecting portraits for Gripsholm in the 16th century — a 1548 inventory already lists 23 portraits among the castle's paintings — and his successors kept adding to it. In 1822 King Karl XIV Johan formally established the collection as the Swedish National Portrait Gallery, the oldest national portrait collection in the world.

More than 800 works hang at Gripsholm today, floor to ceiling in room after room, tracing Swedish faces from the age of Gustav Vasa to the present. A new portrait, the Portrait of Honour, is added to the collection most years, so the gallery is still growing even now, centuries after it began.

King Gustav III, a passionate patron of drama, had an intimate theatre built into one of Gripsholm's round towers between 1772 and 1781, to designs by Erik Palmstedt, who drew inspiration from Palladio's Teatro Olimpico in Vicenza. The circular tower shaped a small amphitheatre seating around sixty.

No performance has been recorded in Gustav III's theatre since 1785, and it survives essentially untouched. The stage set on display is the one used for a performance of Drottning Christina before the royal court, still exactly as it was struck more than two centuries ago, seats and chandeliers included, waiting for a performance that has never resumed.

Because Gripsholm only opens daily in the warmer months, most visitors naturally arrive between mid-May and mid-September — and within that window, a weekday morning is the calmest time to see the state rooms and the Portrait Gallery before the busier midday hours.

If your trip falls outside the summer window, plan for a Saturday or Sunday and the shorter winter hours, and confirm your date is not one of the closed days around Christmas and New Year. Booking your date in advance means your entry is arranged whichever season you travel in, without guesswork on the day you finally arrive at the gate.