The meaning of this
rev. type is obscure, unfortunately.
A British connection? Well, the emperors traveled to
Britain in this year, 208, but the first
types indicating fighting, including one showing the emperors crossing a river on a bridge of boats, belong to 209. Indeed, the Bridge
type of the new
medallion probably belongs to January 208, (1) because the unique
aureus of this
type, in
Paris, was struck from an
obv. die that was carried over from 207, and (2) because we now know that the
type was used on bronze medallions, which were usually produced as New Year's gifts.
Now, the same hypothetical
medallion issue of 1 Jan. 208 also included a
type commemorating the departure of the three emperors for
Britain,
PROF AVG[G]
P M TR P XVI, all three of them on horseback: see my incomplete and somewhat damaged plaster
cast of a unique framed
medallion in the
Vatican, below, from a different
obv. die than the new Bridge
medallion.
Such an expedition
had to be planned months in advance, so it is plausible that a
medallion of 1 Jan. 208 might look ahead to a departure that presumably only occurred several months later, in
spring or early summer 208. But
had Septimius already begun building a
stone bridge connected with
his British campaign by Jan. 208? What major river in
Britain, or en route in
Italy or
Gaul for that matter, could have required such an effort, and deserved commemoration on the coinage?
Perhaps the bridge
had actually been built in 207, in a different connection. It seems plausible from numismatic evidence that
Caracalla may have conducted a campaign in
Mesopotamia in 207, though no such expedition is mentioned in our scanty and fragmentary literary sources. What precise river was bridged remains obscure in either case! The occurrence of the Bridge
type on coins of Septimius only, however, speaks against its connection with an expedition led not by him but by
Caracalla.