The Tenth Iter in the British section of the Antonine road-book has been for many years–indeed for centuries–a standing puzzle in Romano-British history. Of its nine stations the seventh, Mancunium, has always been recognized as Manchester; but the others are not so easily identifiable. The first, third, and fifth reappear in the Notitia Dignitatum towards the end of the section headed item per lineam valli; but it has long been admitted by everyone that they are not therefore necessarily to be sought on Hadrian's Wall itself. Camden, on the strength of an inscription found by Reginald Bainbrigg at Whitley Castle near Alston, identified that fort with Alone, the third station of the Iter; and Horsley, accepting this identification, made the Iter begin at Lanchester and traverse a series of stations lying behind Hadrian's Wall and acting as supports to it, before turning south by way of the Eden and Lune valleys to Manchester. That was a good solution, and indeed the best possible solution, granted the correctness of the equation Alone = Whitley Castle; but it necessitated the complete rejection of the mileages as given in the Iter, since the hundred statute miles from Whitley to Manchester are represented by 83 Roman miles or about 76 statute miles between Alone and Mancunium. Moreover, Camden's identification was unsound. The Notitia places the Third Cohort of Nervii at Alone (spelt in that document Alione) and Bainbrigg's inscription mentioned the Second Cohort. Camden arbitrarily altered the numeral in order to effect the identification.
I.—Hardknot Castle and the Tenth Antonine Itinerary