With the death of Charles VI in 1740, the male Hapsburg line came to an end. His eldest daughter, Maria Theresa, acceded to the throne of the Hapsburg Empire according to the wishes of her father. However, the Electors of both Saxony and Bavaria challenged her right to the throne, basing their claims on the edict of succession issued by Leopold I. Frederick II of Prussia offered to support Maria Theresa's claim if she would cede the greater part of Silesia to Prussia, a condition which was unacceptable. These claims, both dynastic and territorial, led to series of wars collectively known as the War of Austrian Succession (1740 - 1748).

Prague was an early target of invading armies. The city was poorly defended and fell to the first assault on November 25, 1741. This led to a year long occupation of the city by Saxon, Bavarian and French troops, which were supporting the Bavarian Elector. During this period the mail connection with France for the French troops was handled by their own field post. Affixed to this mail was the strait-line cancel.

This was the first postal cancel used in the Czech lands, albeit by a foreign occupying army.