In the Panegyric of Mamertinus on the Emperor Maximian, one of the Augusti, who shared the imperial power with Diocletian, we have the first mention of the Picts. Worthless as the Panegyrists are when we want specific facts, they have the great merit of being cotemporary to the events they allude to; for allusions of a tantalizing and unsatisfactory character is all we get from them. However, Mamertinus is the first writer who mentions the Picts, and he does it in his notice of the revolt of Carausius. More important than this is a passage which gives us an army of Frank mercenaries in the City of London, as early as A.D. 290--there or thereabouts. It is a passage of which too little notice has, hitherto, been taken--"By so thorough a consent of the Immortal Gods, O unconquered Cæsar, has the extermination of all the enemies, whom you have attacked, _and of the Franks more especially_, been decreed, that even those of your soldiers, who, having missed their way on a foggy sea, reached the town of London, destroyed promiscuously and throughout the city the whole remains of that mercenary multitude of barbarians, that, after escaping the battle, sacking the town, and, attempting flight, was still left--a deed, whereby your provincials were not only saved, but delighted by the sight of the slaughter." One German tribe, then at least, has set its foot on the land of Britain as early as the reign of Diocletian; and that as enemies. How far their settlement was permanent, and how far the particular section of them, mentioned by Mamertinus, represented the whole of the invasion, is uncertain. The paramount fact is the existence of hostile Franks in Middlesex nearly 200 years before the epoch of Hengist. Were there Saxons as well? This is a question for the sequel. At present, I remark, that Mamertinus mentions them by name but without placing them on the soil of Britain. They merely vexed the British Seas. Were there any other Germans? Aurelius Victor suggests that there were. A.D. 306, Constantius dies at York, and Constantine, his son, "assisted by all who were about, but especially by Eroc, King of the Alemanni, assumes the empire." Now Eroc had accompanied Constantius as an ally (_auxilii gratii_); so that there were Alemanni in Yorkshire, as well as Franks in Middlesex, with powers, more or less, approaching those of independent populations; at any rate, in a different position from the mere legionary Germans, of whom further notice will soon be taken. In Julian's reign the Picts, Scots, and Attacotti harass the South Britons. This is on the cotemporary and unexceptionable evidence of Ammianus Marcellinus. And the same cotemporary and unexceptionable evidence adds the _Saxons_ to his list of devastators--"Picti, _Saxonesque_, et Scoti, et Attacotti Britannos ærumnis vexavere continuis." Mark the word _continuis_.