Roman Attack on Welsh Druid Island (Anglesey)
Ynys Môn is the island's Welsh name. It first appeared in the Latin as "Mona" in various Roman sources. It was likewise known to the Saxons as Monez. Poetic names include the Old Welsh Ynys Dywyll (Shady or Dark Isle), Ynys y Cedairn (Isle of the Brave), Môn Mam Cymru ("Môn, Mother of Wales"), Y fêl Ynys (Honey Isle), and Ynys Gybi (Holy Island). The English name for Anglesey may be derived from the Old Norse Ǫngullsey (Hook Island). https://en.wikipedia.org/wiki/Anglesey
The word "Mona" is Druid-Akkadian meaning "Supporter" so it would be "The Supporter's Island." Consequently, the word "Supporters" may be what the whole Druid priestly class were called by the native population.
Druid (Supporter) Island
(May 8, 2024) Tacitus says:
Now, however, Britain was in the hands of Suetonius Paulinus, who in military knowledge and in popular favour, which allows no one to be without a rival, vied with Corbulo, and aspired to equal the glory of the recovery of Armenia by the subjugation of Rome's enemies. He therefore prepared to attack the island of Mona which had a powerful population and was a refuge for fugitives. He built flat-bottomed vessels to cope with the shallows, and uncertain depths of the sea. Thus the infantry crossed, while the cavalry followed by fording, or, where the water was deep, swam by the side of their horses.
On the shore stood the opposing army with its dense array of armed warriors, while between the ranks dashed women, in black attire like the Furies, with hair disheveled, waving brands. All around, the Druids, lifting up their hands to heaven, and pouring forth dreadful imprecations, scared our soldiers by the unfamiliar sight, so that, as if their limbs were paralyzed, they stood motionless, and exposed to wounds. Then urged by their general's appeals and mutual encouragements not to quail before a troop of frenzied women, they bore the standards onwards, smote down all resistance, and wrapped the foe in the flames of his own brands. A force was next set over the conquered, and their groves, devoted to inhuman superstitions, were destroyed. They deemed it indeed a duty to cover their altars with the blood of captives and to consult their deities through human entrails.
Comment
Notice the Druids are wearing black. The color of the robes seem to correspond to the ritual or task at hand.
References
Complete Works of Tacitus. Tacitus. Alfred John Church. William Jackson Brodribb. Sara Bryant. edited for Perseus. New York: Random House, Inc. Random House, Inc. reprinted 1942