IDRISID: Idris I, 789-791, AR dirham (2.45g), AH177 (sic), A-419, mint must be Tudgha, but the engraver confused the city name with the following word sana, which he in turn combined with what should be arba' for "4 " (for AH174), the ruler's name in the reverse margin is idris bin 'abd Allah, who ruled AH172-175; an interesting error, VF, R.
Estimate: 120-160 USD