Gaius Suetonius Tranquillus,
The Lives of the Twelve Caesars
“ And it fell out that as he was offering sacrifice in a public temple after his arrival in the province, the hair of a young attendant who was carrying an incense-box suddenly turned white all over his head, and there were some who did not hesitate to interpret this as a sign of a change of rulers and of the succession of an old man to a young one; that is to say, of Galba to Nero. Not long after this lightning struck a lake of Cantabria and twelve axes were found there, an unmistakable token of supreme power. ”
