Watch List notes:

Caracalla, 198 – 217. Sestertius 214, Æ 17.40 g. Laureate, draped and cuirassed bust r.; behind head, silver eagle countermark (Este collection). Rev. Caracalla, accompanied by two officers, standing r. on platform on l., haranguing officer and two soldiers with legionary eagles; behind, vexillum. C 273 var. (AVREL). RIC 525c.
Very rare and a most interesting countermark on obverse (symbol of the Este family).
Brown tone, ragged flan, otherwise very fine