Belisarius begging for an obolus. Belisarius, the greatest of
Justinian's generals, being accused of conspiring against the life of
the emperor, was deprived of all his property; and his eyes being put
out, he lived a beggar in Constantinople. The tale is that he fastened
a bag to his road-side hut, and had inscribed over it, “Give an obolus
to poor old Belisarius.” This tradition is of no historic value.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894