sulla80
Large Seleucid Bronze Coin
This large Antiochus III Seleucid bronze, called "Denomination A" in SC (Houghton & Lorber) appears to be very rare and the best example of this type (SC 1060). The M control mark is unlisted/unknown until now for this coin and the reverse monogram is associated with a longtime Antioch magistrate who was transferred to Asia Minor c. 203 BC [S.C. Part 1 Vol 1] .
Antiochos III Megas (“Antiochos the Great”), was a Seleukid King, born in the period c. 243 - 241 BC, he reigned 223 - 187 BC, and killed in 187 BC leading a raid on a temple treasury in Elymais. He expanded the Seleucid territories and positioned himself as a champion of Asian independance from Rome. A story of diplomatic encounter between a Roman ambassador and Antiochus ends with Antiochus explaining:
"I am a relative of Ptolemy," he said, "and I shall be his father-in-law, although I am not so now, and I will see to it that he renders gratitude to you. I am at a loss to know by what right you meddle with the affairs of Asia when I never interfere with those of Italy." And so they separated without coming to any understanding, and both sides broke into more open threats.
-Appian, Syrian Wars 1.3
In the later years of his reign (circa Dec 190 - Jan 189 BC) Antiochus III lost a decisive battle against Rome who was allied with Eumenes II: the battle of Magnesia which led to a treaty at Apamea, which pushed the Antiochus' control East of the Tuarus mountains.
Thanks to David K., developer/owner of Seleucid resource site AllCoinage, I have a better identification of this coin as SC 1060, resolving clearly the question of mint as Antioch. The mint assignment is supported by SC 1054 which has the same M in the known controls. The M in outer left was not seen before because known examples were too poorly preserved or off struck to show the M on the lower left. Ω/P is referenced in SC Online for this coin (Houghton monogram 607.20).

Seleukid Kingdom, Antiochos III, 223-187 BC, AE, Antioch mint Size: 26.5mm, 11.90g Obv: Laureate head of Apollo right Rev: BAΣIΛEΩ[Σ] ANTIOXOY, Tripod; Ω/P monogram above M to left

Ref:Seleucid Coins (part 1) 1060
This coin is a "Denomination B" which is also a rare coin, especially in this condition. It has a youthful portrait of Antiochos III. I find only 1 sold by CNG in 2005 in ACSearch.

Seleukid Kings of Syria, Antiochos III 'the Great', 223-187 BC, Æ 20mm (8.13 g, 1h), Ekbatana mint
Obv: Diademed head of Antiochus III right
Rev: Nike standing left; anchor to inner left, monograms to outer left [and right]
Ref: SC 1240; SNG Spaer -; Houghton 1162