Suetonius,
The Lives of the Twelve Caesars…
“ A common soldier, who happened to pass that way, spying his feet, and desirous to discover who he was, pulled him out; when immediately recognizing him, he threw himself in a great fright at his feet, and saluted him by the title of emperor. He then conducted him to his fellow-soldiers, who were all in a great rage, and irresolute what they should do. They put him into a litter, and as the slaves of the palace had all fled, took their turns in carrying him on their shoulders, and brought him into the camp, sad and trembling ”
