What does Riding the Circuit mean?

In the U.S., the act, once undertaken by a judge, of traveling within a judicial district (or circuit) to facilitate the hearing of cases.

imperial crisis leads to civil war.

roman forces withdraw from britain as goths attack rome.

odoacer topples romulus augustus

huns attack the empire and drive german peoples ahead of them.

answer; the edward snowden leaks of nsa classified material;