Ioannes 89 is styled a Chaldaean (Ἰωάννης ὁ Χάλδος, ὁ Χαλδίας, or similar: Leo Gramm. 244, 251, 253, Georg. Mon. Cont. 830, 837, 839, Ps.-Symeon 678, 685, 687. In 866 he went on the expedition against Crete and was involved with Basilios 7 in the plot to kill the Caesar Bardas (Bardas 5): Leo Gramm. 244, Georg. Mon. Cont. 830, Ps.-Symeon 678. He conspired with Basilios 7 (Basil I) to murder the emperor Michael III (Michael 11), on 23 September 867; it was Ioannes 89 who struck the first blow and cut off Michael 11's hands and (according to Leo only) who later struck the blows which killed the emperor: Leo Gramm. 251, Georg. Mon. Cont. 837, Ps.-Symeon 685. Subsequently he became strategos of Chaldia; he was found to be plotting against the emperor Basil I (Basil 7) and was crucified on Basil 7's orders by Andreas 18: Leo Gramm. 253, Georg. Mon. Cont. 839 (both read: στρατηλάτης γεγονὼς ἐν Χαλδίᾳ), Ps.-Symeon 687-688 (στρατηγὸς Χαλδίας γενόμενος). See further Winkelmann, Quellenstudien, pp. 87ff., Rangstruktur, p. 107. The date of the murder was 21 April 866 (indiction 14): Theoph. Cont. V 17, p. 238. Presumably identical with Tzifinarites, a Chaldaean, who took part in the murder of the Kaisar Bardas 5, at Kepoi, on 21 April of indiction 14 (μεθ' ὧν Χάλδος τις παρεύρητο, ᾧ Τζιφιναρίτης ἐπώνυμον): Genesius IV 23. Tzifinarites was presumably either a nickname or a family name.

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