497 
of antiquity give definiteness and certainty to our historical 
conceptions. When we merely read history, its characters 
pass before us very much as figures in a phantasmagoria ; 
but when we see the armour in which the men of fifteen 
centuries ago fought, the household vessels in which they 
prepared or took their food, and the coins which passed 
through their hands, we feel that they were realities and of 
kin to ourselves. 
The series of these coins begins at a time of deep degra- 
dation and misfortune to the Roman empire. Valerian had 
been made captive by Sapor, King of Persia, who made use 
of him as a footstool to mount his horse; and, after death, 
caused his skin to be stuffed and hung up as a trophy in one of 
the temples. During the reign of his son Gallienus, the dis- 
memberment of the empire seemed imminent; its frontiers 
suffered from the invasion of the barbarians, several provinces 
made themselves independent, and the physical calamities of 
earthquakes, pestilences, and inundations were added to poli- 
tical misfortune. But a better time succeeded. Claudius 
Gothicus repelled the Alemanni from Italy, and the Goths 
from Greece ; Aurelian re-established the Roman power in 
the east, subdued the factions of ^ Rome, and surrounded the 
city with a wall of such strength and circuit that she seemed 
secure from the attacks of the barbarians. By him and his 
successors, Tacitus and Probus, the unity of the empire was 
restored and upheld. 
The most remarkable result of the state into which the 
imperial power fell, during the reign of Gallienus, was the 
springing up in all parts of those whom history calls the 
Thirty Tyrants, though without any great propriety, since 
their number did not literally amount to thirty, nor did they 
deserve the appellation of tyrants, if that name is understood 
to convey the idea of usurped power, or a cruel and selfish 
use of it. The talents of Gallienus were by no means con- 
