When Diocletian ascended the throne of the Caesars on September 17, 284, there was still in the field against him an army under the command of Carinus, the elder son of Carus. Carinus was killed by one of his own officers in the battle of the Margus (285), and Diocletian was thus left undisputed master of the Empire. Of all the emperors who up till now had reigned in Rome none had succeeded in emancipating himself so completely from outside influence, whether wielded by the Senate or by the Praetorian Prefect or by any one else, as did this native of Illyria. It was left for him to deprive the Senate of the last of its fictitious prerogatives—prerogatives which had extended even into the domain of army administration—and to become in the fullest sense of the term the founder of an absolute monarchy.

The original purpose served by this curious panel of mosaic and marble (plate I), which is decorated with scenes from the life of Achilles, has not yet been determined, nor has any successful attempt been made either to date it or to assign it definitely to any school or centre of art. The mosaic which occupies the centre and corners is probably rightly attributed to the Cosmati, who made the ‘ambon’ in S. Maria in Ara Coeli, of which this panel formed a part. The circular band of marble, decorated in relief, is generally regarded as the top of a puteal or well-head although, as has been observed, it is hardly consistent with the practical sense of the Greeks and Romans to cover with decoration a surface of marble so liable to rough usage. More probably the band formed the border of a large shallow bowl, a possibility not considered heretofore owing to the difficulty of close examination arising out of its post-classical use.

Now that Septimius Severus can no longer be credited with the original construction of any one of the lines which at various times marked the British frontier, it is necessary to ask what meaning, if any, can be attached to the statements of ancient writers who ascribe to him the building of the British Wall. It may therefore be worth while to collect the available evidence as to the state of the frontier in the time of Severus, and the structural work which he may have carried out upon it.

Livy i, 18, 6, describing the accession of the second King of Rome, provides food for much thought on the part of those who are interested in the religious ideas of early Italy, and gives us the material for a brisk controversy which is far from being settled. Despite therefore the familiar contents of this passage, I quote the part of it which is most important for our purpose.

Accitus … de se quoque deos consuli iussit. inde ab augure, cui deinde honoris ergo publicum id perpetuumque sacerdotium fuit, deductus in arcem, in lapide ad meridiem uersus consedit. augur ad laeuam eius … dextras ad meridiem partes, laeuas ad septentrionem esse dixit.

Numa then is facing south ; the augur is facing east. Both are engaged in the same important ceremony. Why do they not look the same way, but at right angles to each other, and what is the significance of their respective attitudes ?

In 1918 the Museum of Archaeology and Ethnology in Cambridge acquired with Professor Babington's collection a hoard of some-what unusual objects. They were found in 1857 in Willingham Fen, Cambridgeshire, south of the River Ouse or Old West River, on a spot, which is now no longer fen but a field known as ‘The Hempsalls,’ two and a half miles north-west of Cottenham and eight miles north of Cambridge. They had been placed in a wooden box, no doubt for concealment in a convenient place. Their curious character makes them worthy of more detailed notice than they have hitherto received.

What was the purpose of the small bone tags, mostly found near Rome, with legends usually containing the following elements: (i) a name in the nominative; (ii) a name in the genitive; (iii) ‘sp.,’ ‘spectavit’ or ‘spectat. num.’; (iv) a date specifying the day, month and year?

At Margidunum (Notts), halfway between Leicester and Lincoln, I have been carrying on excavations for several years, through the kindness of the owner, Mr. F. W. Dobson, J.P., in one of the three fields of the site, the only field at present available. Although much remains to be done, my results serve already to substantiate the surmise that this camp formed a link in the chain of Claudian frontier-posts established by P. Ostorius Scapula in A.D. 47, between the Severn and the Trent, when (according to Bradley's generally accepted emendation of Tacitus, Annals, xii, 31, 32) detrahere arma suspectis cunctaque cis Trisantonam et Sabrinam fluvios cohibere parat. Nothing was known of this camp beyond the name Margidunum, which occurs twice in the Antonine Itineraries (Iter 6 from London to Lincoln, and Iter 8 from York to London). It is about 8 acres in extent, and is rhomboidal in outline (plan, plate VIII), recalling in this respect the Claudian camp of Hofheim. The Fosse Way, which now traverses it diagonally, was not the original Roman road. In those days, undrained marshes protected the camp on the south, and the approach from this direction was by a short causeway (bordered by ditches), which can still be traced from a natural ridge that comes near the SE. angle of the camp. Thence the main road of the camp ran diagonally across it to NW., and from the NW. angle another well-marked causeway leaves the camp and can be traced for a considerable distance to the NE.; it is still so conspicuous that it is known locally as the ‘hump.’ The entrances to the camp have not yet been explored, for the fields in which they occur are unfortunately not available for excavation.

§ 1. The exact measure of the originality of Diocletian's statesmanship has not yet been taken. ‘Like Augustus,’ said Gibbon, ‘Diocletian may be considered the founder of a new empire’ and these words express the accepted view. In the whole work of pulling the Empire together, which went on from A.D. 270 to 330, the three outstanding actors were Aurelian, Diocletian, and Constantine, and the part played by Aurelian was indispensable for the restitutio orbis. It was he who destroyed the Principate, notwithstanding the negligible episode of Tacitus. It was he who founded the autocracy; Diocletian who regularized and systematized it. Two new things Diocletian certainly did, one of which was a success and the other a failure though not a fruitless one. His division of the Empire into Dioceses was permanent for nearly three hundred years. His throne system led to disaster and disappeared; yet the territorial quadripartition which it involved was afterwards stereotyped in the four Prefectures, and Nicomedia pointed to Constantinople. But in many of the other changes which distinguished the Empire of Constantine from the Empire of Severus and which have generally been regarded as inventions of Diocletian, it is becoming clear that he was not the initiator but was only extending and systematizing changes which had already been begun. The separation of civil from military powers in provincial government had been initiated by Gallienus (the importance of whose reign has in recent years been emerging). Some of the characteristics which mark the military organization of the fourth century had come before Diocletian's accession. Mr. Mattingly's studies in the numismatic history of the third century have been leading him, as he tells us, to similar conclusions.

The account of the Castra Peregrinorum which follows, has been compiled by Mr. Baillie Reynolds mainly from notes taken by me in 1904–9. These notes have proved inadequate in some details, largely owing to the circumstances of the discovery of the remains, which were found at considerable intervals of time and of space, so that a comprehensive view of them could never be obtained.

New light has been thrown during the last year on the question of the date of the Castra Peregrinorum owing to the discovery, by French excavators in Tunis, of an inscription of the reign of Trajan, wherein a Princeps Peregrinorum is mentioned. In view of this fresh evidence, it seems desirable to complete the account of the remains of the Castra Peregrinorum itself by re-assembling all that is known about the body of troops quartered in those barracks.

Professor Percy Gardner published in this Journal a most interesting portrait-head belonging to the Ashmolean Museum, undoubtedly a portrait of Livia. As good portraits of the Empress are very rare, the little-known head in the Hermitage Museum deserves further notice. The head in question belongs to the original stock of the Museum, but it is unknown how it found its way there. In the first notice extant Guédéonoff described it as a ‘portrait of a Roman lady.’ Kieseritzky proposed the name ‘Messalina.’ In my Catalogue of the Museum and in my Roman Portraits in the Hermitage Museum, I have called it Livia.