In 196 AD, during the tumultuous reign leading up to the Year of the Five Emperors, the Roman historian Cassius Dio documented a peculiar atmospheric phenomenon over the city of Rome. According to his account in Historia Romana, a substance resembling wool or fine fibers descended from the sky in large quantities, falling over the city and temporarily settling on rooftops and streets before dissolving.
This event is categorized by modern UAP researchers as an early instance of what would later be termed "angel hair" — a fibrous, cobweb-like material that has been reported falling from the sky in association with UFO sightings across multiple centuries and cultures. The phenomenon was observed in broad daylight by numerous Roman citizens, and Cassius Dio considered it significant enough to include in his comprehensive history of Rome.
Angel hair incidents have been reported worldwide in the modern era, most notably during the 1952 Oloron-Sainte-Marie and Gaillac sightings in France, where cigar-shaped objects trailing the material were observed by hundreds of witnesses. Analysis of modern angel hair samples has typically yielded boron, silicon, magnesium, and calcium compounds — though samples degrade rapidly on contact with air and human skin, making laboratory analysis consistently difficult.
The 196 AD Roman record predates the modern UFO era by nearly 1,800 years yet describes the same substance with the same characteristics — transient, fibrous, dissolving on contact — that would recur in documented cases through the twentieth century. Whether the Roman incident involved the same aerial phenomenon as modern cases remains unknown, but Cassius Dio's status as one of antiquity's most reliable historians lends the account a degree of historical credibility unusual for this era.