Coat of arms of the Polish–Lithuanian Commonwealth

The coat of arms of the Polish–Lithuanian Commonwealth represented the union of the Crown of the Polish Kingdom and Grand Duchy of Lithuania. While the coat of arms remained mostly unchanged throughout the Commonwealth's tenure, as different kings were elected it would be defaced with their personal arms and other features, such as the Order of the Golden Fleece (when the armiger was a member) or the Order of the White Eagle for later kings.

Source: Wikipedia — Coat of arms of the Polish–Lithuanian Commonwealth (CC BY-SA 4.0)