Golden bull

Not to be confused with Golden calf.
Imperial chrysobull of Alexios III of Trebizond, 1374
The gold seal of the Golden Bull of 1356 issued by Holy Roman Emperor Charles IV
The Golden Bull of 1242 by Béla IV to inhabitants of Zagreb in Croatia

A golden bull or chrysobull was a decree issued by Byzantine emperors and monarchs in Europe during the Middle Ages and Renaissance.