There are some views from the train which remain forever in the memory. A glimpse of the monastery of Melk from the train heading towards Vienna is one. Another which lingers happily is the extraordinary sight of the great basilica at Esztergom from the north side of the Danube just as the Budapest-bound train crosses the border from Slovakia into Hungary. But even these two remarkable views are as nothing compared with the view to the south as the train from Gdańsk crosses the River Nogat at Malbork.

The views of the ecclesiastical buildings at Melk and Esztergom may be remarkable, but both buildings are self-explanatory: they are expressions of Catholic might. That glimpse of the castle at Malbork suggests something altogether more complicated, evoking as it does images of Teutonic power and Hanseatic authority. Why does this striking red-brick castle stand amid Polish meadows? Who built it, and why?

Malbork Castle (zamek w Malborku in Polish) is Europe’s largest brick castle and a fine place to start investigating the red-brick Gothic architecture of the Baltic region. The castle is widely acclaimed for its antiquity with many writers commending it as the greatest work of mediaeval secular architecture in Europe, and some commenting that its completeness attests to the quality of 14th-century craftsmanship.

Such plaudits gloss over the fact that 200 years ago Malbork was in a woeful state of disrepair; its reconstruction in the 19th century was an important assertion of Prussian power in the region.