Eustolios 1 was a basilikos chartoularios; owner of a seal dateable to the eighth or ninth century: Schlumberger, Sig., p. 465, no. 7 (facsimile). Obv.: invocative monogram of Θεοτόκε βοήθει with the legend τῷ σῷ δούλῳ. Rev.: +Ευς - τολη(ῳ) β(ασιλικῷ) - χαρτου - λαρη(ῳ). Possibly this is the same seal as those published by Konstantopoulos, JIAN 6, 273 and Schlumberger, Sig., p. 369 (or possibly another specimen of the same?), where the text is read as: Ευστολη βασιλικου χαρτοφ[υ]λακος. The chartophylax was an ecclesiastical official; evidence is lacking for a basilikos chartophylax, and the seal appears to have been misinterpreted by Konstantopoulos (and see also Eustolios 2).

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