12 THE ROMAN OCCUPATION 



this was not the only function of this garrison. It was 

 there also to keep the peace in the lowlands, ready to 

 crush a rising if such occurred. So far as we know, its 

 services in this matter were never needed. In the more 

 important work of keeping the peace along the hills and 

 frontiers, it was continuously and seriously engaged. 



The organisation of the garrison proceeded on the 

 normal lines of the Roman army. That army, as it was 

 under the Empire, consisted of two principal grades of 

 troops — legions and auxiliaries. The legion was a body 

 of 5,000 to 6,000 heavy infantry, recruited from the 

 civilised and Roman or Romanized portions of the Italian 

 or provincial populations, and constituting in size and 

 morale and fighting strength the dominant element in the 

 army, but an element which, owing to its very size, was 

 a cumbrous as well as a powerful weapon. Three legions 

 garrisoned Britain, one in each of three large fortresses — - 

 York, Chester and Caerleon. These formed the basis on 

 which the defence of the province relied. But besides the 

 legions, we have also the troops of the second line, the 

 so-called auxiliaries. These were levied from among 

 the subjects (but not the citizens) of Rome. They were 

 less well-paid, less favoured in conditions of service, less 

 reliable in warfare ; they were also grouped together in 

 less potent units of 500 or 1,000 men. But they had 

 advantages. They were handier units, and they often 

 included cavalry, bowmen, light troops. Accordingly 

 they were stationed, not in large hiherna but in small 

 castella, each covering some three or four or six or eight 

 acres. These castella in most of their general arrange- 

 ments were only a simplified variety of the hiherna. They 

 were rectangular walled areas with four gates planted 

 symmetrically in opposite pairs, central principia or 

 headquarters in the middle, and barracks and storehouses 



