SISINNIUS II. — He was Patriarch of Constantinople (996–998). Two synodal acts of his are preserved concerning marital legislation and one concerning Metropolitan Nicholas of Alania. According to V. Grumel, he would not have reissued Photius’s encyclical against the Filioque; but according to Michel (Byzantinische Zeitschrift, 28 [1938], pp. 454–56), this doubt is not justified in light of a manuscript in Moscow.
BIBL.: V. Grumel, Les regestes des actes du patriarcat de Costantinople, III, I, Costantinopoli 1936, nn. 804–14, pp. 231–39; Fliche - Martin - Frutaz, VII, pp. 140–41.