Egypt. Alexandria. Antoninus Pius, 138-161. Tetradrachm. (Billon, 23.20 mm, 14.28 g). Dated RY 20 = AD 156/7. ANTωNIN[OC] CЄB ЄYCЄB Laureate, draped and cuirassed bust right. Rev. The Emperor seated on platform, left, extending hand, holding sceptre; to left, soldier standing, holding spear and offering wreath; to right, soldier standing, raising hand, holding parazonium(?); L-K (date), in field. RPC IV, 4.1825.6 (this coin cited). Dattari-Savio Plate 107, 8041 (this coin). Emmett 1384. Extremely rare, only seven specimens listed in RPC. Good Very Fine/Very Fine. From the Dattari Collection. Ex Naville Numismatics Ltd., Auction 54, 15.12.2019, lot 314. Rare tetradrachm of the 20th year of the reign of Antoninus Pius (156-157 A.D.). On obverse the bust of the emperor has a markedly senile appearance but treated in an aulic way without accentuating the shortcomings of his advanced age. Coin celebrating the "vicennalia" of the sovereign as can be seen from the engraved scene on the reverse that shows the emperor enthroned above a high pedestal replying to the greeting of Alexandria honouring him with the crown at the bottom left, while in the lower right appears a soldier who greets the sovereign. Prestigious specimen already belonging to the collection of Giovanni Dattari.