Anchialus - A settlement in Thrace
Possibly founded in the 5th or 4th century BC as a colony of Apollonia, Anchialos was mentioned in Strabo's Geographica as a small town. It was briefly captured by Messembria (Nesebar) in the 2nd century BC, but reconquered by Apollonia and its fortified walls destroyed.

The western Black Sea coast was ultimately conquered by the Romans under Marcus Licinius Crassus in 29-28 BC after continuous campaigns in the area since 72-71. In the early 1st century AD Anchialos was the centre of a strategia of the vassal Odrysian kingdom, and the town had a Thracian population in the 6th century AD according to the early Byzantine historian Procopius.

After 681 and the formation of the First Bulgarian Empire to the north Anchialos played an important role in many conflicts between the two empires. After the Ottoman invasion of the Balkans in the 14th century, Anchialos remained a Byzantine bulwark until submission in 1453 together with Constantinople.

Modern location: Pomorie, Bulgaria

(1) Gordian III | Tranquillina 241-244 AD
AE unit Anchialus
Obverse: [AΥT K M ANT Γ]OΡΔIANOC AΥΓ CAB / TΡANKΥΛ / ΛINA, confronted busts of Gordian III and Tranquillina
Reverse: OΥΛΠIANΩN - AΓXIAΛEΩN, Tyche standing l., holding rudder and cornucopiae.
Ref: Varbanov II, 735
(2) Septimius Severus 193-211 AD
AE unit Anchialus
Obverse: laureate, draped and cuirassed bust right from behind; AV K Λ CEΠ_CEVHPOC
Reverse: prize urn set upon agonistic table with decorated legs, CEBHPIA / NVMΦIA below the table top (between the legs); flanked on each side by a palm frond; OVΛΠIANΩ_N AΓXIAΛ / EΩN
Ref: AMNG II 492; SNG Copenhagen -; Varb...