Gävle Castle is the northest one of so-called Vasa castles, built by Gustav Vasa of Sweden or his sons. The construction started in 1583 by the religious King John III of Sweden. The design was made by Willem Boy and the center of castle was a chapel. The castle was completed in 1597, five years after John's death.
In 1727 the chapel and the top floor were destroyed by fire. Gävle castle stayed damaged until 1741, when it was agreed to rebuilt. The current appearance dates from the design made by Carl Hårleman. In 1754 the reconstruction was complete.
References:The historical centre of Briançon is a strongly fortified town, built by Vauban to defend the region from Austrians in the 17th century. Its streets are very steep and narrow, though picturesque. Briançon lies at the foot of the descent from the Col de Montgenèvre, giving access to Turin, so a great number of other fortifications have been constructed on the surrounding heights, especially towards the east.
The Savoyards made two raids into French territory in 1691 and 1692. As a result, Vauban was dispatched to inspect the frontier defences, which had been ill-equiped to deal with the attack from Savoy. He returned to the area in 1700 to check on the progress that had been made since his first visit. When Vauban visited Briançon, work on the defences had already started under a local engineer, Monsieur d"Angrogne in 1692.