Marcianopolis is spelled out in Greek starting at 12:00 on the reverse.
I bought this coin for several reasons-- the remarkable smooth green patina, the remarkably long obverse legend, and the fact it cost about the same as the first Macrianus and Diadumenian I had bought 20 years earlier before the wall came down. Those of you who have begun collecting in the past 15 years probably do not know that the two-headed coins of Marcianopolis and all those common coins of Nicopolis and other cities in the region used to be quite unusual. Now they are everywhere due to the flood of coins released when the wall came down and a continuing supply from the countries on the west side of the Black Sea. Before the 1990s, the West had little access to those coins.

Macrinus and Diadumenian, 217-218
28-27 mm. 11.97 grams. 6:00
Marcianopolis (Hristova and Jekov) page 108, 6.24.29.3.
Magistrate Pontianus
The name Macrinus begins at 1:00 and Diadumenian begins with the second-last letter of the second last horizontal line.
-- Warren