Constantine entered Constantinople on a "horse caparisoned with gilded saddle clothes and golden bridles and bearing on his head the "kamelaukion", or diadem, which the sovereign alone was authorized to wear and then only on 'a great public festival of the Lord'". Justinian II's son and co-emperor Tiberius, along with Patriarch Kyros, senators, nobles, clerics, and many others, greeted Constantine at the seventh milestone from the city in the style of an imperial "adventus". Justinian II was in Nicaea at the time and urged the pontiff to meet him in Nicomedia. The "Liber pontificalis" recounts a bizarre scene of the crowned emperor prostrating himself before the pope, but a more mutual greeting is probable. That Sunday, Justinian II received communion from the hands of the pope and issued a vague confirmation of the various privileges of the Roman See.