During the Thirty Year War (1618 – 1648) the government of Innsbruck obtained permission to erect a fortress on the lands of the Freising Monastery in the narrowest part of the valley. It was built between 1632 and 1634.
On the festive occasion of the dedication of this ravine-like valley passage, it was named after the shrewd Princess Claudia de´Medici, who was personally present.

Simultaneously, at the end of Leutaschtal valley, the so-called 'Schanz' was also constructed. Porta Claudia was not attacked during the Thirty Year War. Around 1670, it was expanded according to the plans of Christoph Gumpp.
In the course of the 'Bavarian Uprising' in 1703, Prince Max Emanuel
II. succeeded in taking Porta Claudia in a bold and unexpected attack. When the occupying Bavarian forces exploded the ammunitions stores, it caused immense destruction.

However, the fortress was soon rebuilt. When Goethe passed through here on his Italian Journey in 1786, he noted, 'Near Scharnitz, one arrives in the Tyrol. The border is closed by a wall which locks off the valley and merges with the mountain massif.
It looks quite attractive. On one side, the cliffs are fortified, on the other, they shoot up vertically.'

 In 1805, during the Napoleonic Wars, the French Marechal Ney,