Flag of the Duchy of Teschen

The oldest image of the Duchy of Teschen flag or banner was shown on the personal seal of the first duke, Mieszko I.

(As a vassal of the Habsburgs, in their capacity of the Bohemian kings, he was involved in anti-Ottoman wars in territory of Hungary and Moravia.)

[3] The ducal banners, which bore the image of golden eagles in a crown on a blue background, were used until the death of the last Piast ruler, Elizabeth Lucretia (†1653).

From the end of the 13th century, the shield of the dukes of Teschen was a golden eagle facing left in a blue field.

Some foreign sources, such as the Stockholm Codex Bergshammar (from 1430 to 1436) show the Teschen eagle with a red beak, tongue, and claws.