[2] The builders constructed the tower from huge boulders, according to traditions of the Italian fortification style then dominant in Europe.

The tower was named for a legendary king of Norway, Olaf Sacred, who confirmed Christianity in Scandinavia and was later canonised.

Before attaining the royal throne of Sweden, Karl Knutsson (Bonde) took residence in Vyborg in 1442 and began strengthening and expanding the castle.

He constructed new premises and strengthened the castle with new walls and towers, arranging it on the model of the European cities of that time.

[5] In the middle of 16th century Swedish king Gustav Vasa reconstructed and strengthened a fortress for expansion of borders of the state on the east.

Instead of taking actions to strengthen the castle as a military fortress he began to arrange balls and tournaments which demanded considerable expenses.

King Gustav sent an army to conquer Vyborg and count Johan von Hoya fled to Lübeck.

Поэтому большинство домов и помещений стоят без крыш, все в таком упадке, что невозможно обеспечить оборону замка…Translated: First, here, in the castle nobody cares of building.

[6] During the Great Northern War Russian armies under Peter I took all the fortresses of Karelia and Ingria: in 1703–1704 – Nyenschantz, Jama, Koporye, Noteburg, and Ivangorod.

These ignited the dome of the tower and from there the fire was thrown down on buildings standing nearby, consuming all of Vyborg Castle in flames.

[3] Tower restoration was undertaken by the engineer corps under Colonel E. Lezedov on the orders of Russian Military Office in 1891–1894.