the positions of the fortresses where we find the legions presently posted. They agree also with the three main groups of Roman roads which radiate from London: (1) the south-west route to Silchester, and thence by branches to Winchester, Exeter, Bath, South Wales; (2) the Midland “Watling Street,” by St. Albans to Wroxeter and Chester; (3) the eastern route to Colchester, Cambridge, and Castor near Peterborough, to Lincoln.[308] In any case there can be little doubt that by A.D. 47 or 48--within four or five years of the first landing--the Roman troops had reached the basins of the Humber and the Severn, as Mommsen observes (p. 176). This much is plain from the fact that Ostorius, who came out in 47, had at once to deal with the Iceni of Norfolk, the Decangi of Flintshire, the Brigantes of Yorkshire, the Silures of Monmouthshire (Tac. _Ann._ xii. 31). But the difficult corruption of Tacitus (_ibid._), _cuncta castris antonam et Sabrinam fluvios cohibere parat_, is probably to be emended (with Dr. H. Bradley, _Academy_, April and May 1883) _cuncta cis Trisantonam_, _i.e._ the Roman frontier at the moment was, roughly, Severn and Trent. This is preferable both to Mommsen’s suggestion (given above, p. 176 note) and to mine (_Journ. Phil._ xvii. 268). The older and more violent remedy, _Avonam inter et Sabrinam_, though revived in the text of the second edition of Furneaux’s _Tacitus_ (1907), is pretty certainly wrong; indeed, it is not Latin. It would seem then that, by 47 or 48, practically the whole lowlands were in the hands of the Romans. Whether Chester had already been occupied or (as seems likelier) was first garrisoned when Ostorius attacked the Decangi, must remain uncertain; it must in any case have been occupied soon (_Eph. Epigr._ vii. 903; Domaszewski, _Rhein. Mus._ xlviii. 344). Caerleon, connected by Mommsen with Tac. _Ann._ xii. 32, presents more difficulty, since it has yielded hardly any datable remains earlier than about A.D. 70-80; however, no other site can be suggested on our present evidence for the _hiberna_ of the Second Legion Augusta before 70. Wroxeter rests its claim to a fortress on two early inscriptions of Legio xiv. (_Vict. Hist. Shropshire_, i. 243, 244), and this may be adequate, though Domaszewski doubts it. The course of Watling Street seems to show that Wroxeter was occupied before the troops pushed on to Chester.