Complex sentence: St. Stephen's Purse, the Imperial Bible, and the so-called Saber of Charlemagne were kept in Aachen until 1794, which gave them the name Aachener Kleinodien ("Aachen jewels").
Split into simpler sentences: St. Stephen's Purse, the Imperial Bible, and the so-called Saber of Charlemagne were kept in Aachen until 1794. That is why the lesser part is called Aachener Kleinodien ("Aachen jewels").