Marvellous work, David.
Never having seen such a coin before, I had wondered if it was a coin at all, but a medallion. Though I realised it was perhaps Byzantine, I hesitated to say so. The lettering confused me.
With your identification, I found these web references, which others may be interested in following:
Basil II, 10 January 976 - 15 December 1025 A.D
Byzantine Coinage, c.950 to 1204AD
Byzantine coins
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Class A2 anonymous follis. +EMMANOVHA IX-XC, Nimbate bust of Christ holding book of gospels / +IhSUS / XRISTUS / bASILEU / bASILE in four lines, adornments above & below.
The reign of Basil II (Macedonian Dynasty, 976-1025 CE) coincides with the original
Cyrillic alphabet as a writing system developed in the First Bulgarian Empire in the tenth century to write the Old Church Slavonic liturgical language.
Solomon