Egypt. Alexandria. Diocletian, 284-305. Tetradrachm (Billon, 20.80 mm, 7.61 g) dated RY 9 (= 292-293) ΔΙΟΚΛΗΤΙΑΝΟϹ ϹЄΒ Laureate, draped and cuirassed bust of Diocletian right. Rev. ENA TOY L (date) within wreath tied at top with medallion. Dattari-Savio pl. 285, 5788 (this coin). Geissen 3265 (this coin cited). Emmett 4084. Cf. SAVIO A., Tetradrammi alessandrini, pp. 190-196. About Extremely Fine. Ex Giovanni Dattari Collection 5788. Ex Naville Numismatics Ltd. 41, 24.06.2018, lot 379. With the advent of Diocletian, a great general and brilliant politician, the institutional and administrative composition of the Roman Empire was structurally modified through the creation of the Tetrarchy, with the territory divided into East and West, respectively governed by an Augustus and a Caesar, an organization inaugurated in March 293 AD and coinciding with the minting year of our superb and rare tetradrachm, already belonging to the famous Giovanni Dattari Collection. A coin of large size, excellent original chocolate-brown patina, in practice uncirculated.