A note from the year 1436 identifies the owner of this sapphire ring as Duke Ernest the Iron (1377–1424 CE).

A note from the year 1436 identifies the owner of this sapphire ring as Duke Ernest the Iron (1377–1424 CE). This makes it the oldest, unequivocally attributable object inventoried among the medieval treasures of the House of Habsburg. Now housed at the Kunsthistorisches Museum in Vienna