"One of the most notable features of the church is the
Männleinlaufen, a mechanical clock that commemorates the
Golden Bull of 1356. The clock was installed in the church between 1506 and 1509. The Holy Roman Emperor is shown seated with the prince-electors surrounding him.
The clock mechanism is activated at midday, when a bell is rung to start the sequence and is followed by the trumpeters and drummer. Then there is a procession of the electors around the figure of the Holy Roman Emperor." -- Wikipedia