Most of the primary sources treating Photios's life are written by persons hostile to him. Modern scholars are thus cautious when assessing the accuracy of the information these sources provide.
b[›] Little is known of Photios's origin and early years. It is known that he was born into a notable family and that his uncle
Tarasios had been the Patriarch of Constantinople from 784–806 under both Empress
Irene (r. 797–802) and Emperor
Nikephoros I (r. 802–811).
 During the second
Iconoclasm, which began in 814, his family suffered persecution since his father, Sergios, was a prominent
iconophile. Sergios's family returned to favor only after the restoration of the icons in 842.
 Certain scholars assert that Photios was, at least in part, of
c[›] while other scholars merely refer to him as a "
 Byzantine writers also report that Emperor
Michael III (r. 842–867) once angrily called Photios "
Khazar-faced", but whether this was a generic insult or a reference to his
ethnicity is unclear.
Although Photios had an excellent education, we have no information about how he received this education.
d[›] The famous library he possessed attests to his enormous erudition (theology, history, grammar, philosophy, law, the natural sciences, and medicine).
 Most scholars believe that he never taught at
Magnaura or at any other university;
 Vasileios N. Tatakes asserts that, even while he was patriarch, Photios taught "young students passionately eager for knowledge" at his home, which "was a center of learning".
 He was a friend of the renowned Byzantine scholar and teacher
Leo the Mathematician.
Photios says that, when he was young, he had an inclination for the monastic life, but instead he started a secular career. The way to public life was probably opened for him by (according to one account) the marriage of his brother Sergios to Irene, a sister of the Empress
Theodora, who upon the death of her husband Emperor
Theophilos (r. 829–842) in 842, had assumed the regency of the Byzantine Empire. Photios became a captain of the guard (
prōtospatharios) and subsequently chief imperial secretary (
protasēkrētis). At an uncertain date, Photios participated in an embassy to the
Patriarch of Constantinople
Photios's ecclesiastical career took off spectacularly after
Bardas and his nephew, the youthful Emperor Michael, put an end to the administration of the regent
Theodora and the
logothete of the drome
Theoktistos in 856. In 858, Bardas found himself opposed by the then Patriarch
Ignatios, who refused to admit him into
Hagia Sophia, since it was believed that he was having an affair with his widowed daughter-in-law. In response, Bardas and Michael engineered Ignatios's deposition and confinement on the charge of treason, thus leaving the patriarchal throne empty. The throne was soon filled with a kinsman of Bardas, Photios himself; he was tonsured on December 20, 858, and on the four following days he was successively ordained lector, sub-deacon, deacon and priest. He was consecrated as Patriarch of Constantinople on Christmas Day.
The deposition of Ignatios and the sudden promotion of Photios caused scandal and ecclesiastical division on an ecumenical scale as the
Pope and the rest of the western bishops took up the cause of Ignatios. The latter's deposition without a formal ecclesiastical trial meant that Photios's election was uncanonical, and eventually
Pope Nicholas I sought to involve himself in determining the legitimacy of the succession. His legates were dispatched to Constantinople with instructions to investigate, but finding Photios well ensconced, they acquiesced in the confirmation of his election at a synod in 861. On their return to Rome, they discovered that this was not at all what Nicholas had intended, and in 863 at a synod in Rome the pope deposed Photios, and reappointed Ignatius as the rightful patriarch, triggering a
schism. Four years later, Photios was to respond on his own part by calling a Council and
excommunicating the pope on grounds of heresy – over the question of the double procession of the
 The situation was additionally complicated by the question of
papal authority over the entire Church and by disputed jurisdiction over newly converted
This state of affairs changed with the murder of Photios's patron
Bardas in 866 and of Emperor Michael III in 867, by his colleague
Basil the Macedonian, who now usurped the throne. Photios was deposed as patriarch, not so much because he was a protégé of Bardas and Michael, but because Basil I was seeking an alliance with the Pope and the western emperor. Photios was removed from his office and banished about the end of September 867, and Ignatios was reinstated on November 23. Photios was condemned by the
Council of 869–870, thus putting an end to the schism. During his second patriarchate, however, Ignatios followed a policy not very different from that of Photios.
Not long after his condemnation, Photios had reingratiated himself with Basil, and became tutor to the Byzantine emperor's children. From surviving letters of Photios written during his exile at the Skepi monastery, it appears that the ex-patriarch brought pressure to bear on the Byzantine emperor to restore him. Ignatios's biographer argues that Photios forged a document relating to the genealogy and rule of Basil's family, and had it placed in the imperial library where a friend of his was a librarian. According to this document, the Byzantine emperor's ancestors were not mere peasants as everyone believed but descendants of the
Arsacid Dynasty of Armenia.
 True or not, this story does reveal Basil's dependence on Photios for literary and ideological matters. Following Photios's recall, Ignatios and the ex-patriarch met, and publicly expressed their reconciliation. When Ignatios died on October 23, 877, it was a matter of course that his old opponent replaced him on the patriarchal throne three days later. Shaun Tougher asserts that from this point on Basil no longer simply depended on Photios, but in fact he was dominated by him.
Photios now obtained the formal recognition of the Christian world in a
council convened at Constantinople in November 879. The legates of
Pope John VIII attended, prepared to acknowledge Photios as legitimate patriarch, a concession for which the pope was much censured by Latin opinion. The patriarch stood firm on the main points contested between the Eastern and Western Churches: the demanded apology to the Pope, the ecclesiastical jurisdiction over
Bulgaria, and the addition of the
filioque to the
Nicene creed by the Western church. Eventually, Photios refused to apologize or accept the filioque, and the papal legates made do with his return of Bulgaria to Rome. This concession, however, was purely nominal, as Bulgaria's return to the
Byzantine rite in 870 had already secured for it an autocephalous church. Without the consent of
Boris I of Bulgaria (r. 852–889), the papacy was unable to enforce its claims.
During the altercations between Emperor Basil I and his heir
Leo VI, Photios took the side of the Byzantine emperor. In 883, Basil accused Leo of conspiracy and confined the prince to the palace; he would have even have Leo blinded had he not been dissuaded by Photios and
Stylianos Zaoutzes, the father of
Zoe Zaoutzaina, Leo's mistress.
 In 886, Basil discovered and punished a conspiracy by the domestic of the
John Kourkouas the Elder and many other officials. In this conspiracy, Leo was not implicated, but Photios was possibly one of the conspirators against Basil's authority.
Basil died in 886 injured while hunting, according to the official story. Warren T. Treadgold believes that this time the evidence points to a plot on behalf of Leo VI, who became emperor, and deposed Photios, although the latter had been his tutor.
 Photios was replaced by the Byzantine emperor's brother
Stephen, and sent into exile to the monastery of Bordi in
Armenia. It is confirmed from letters to and from
Pope Stephen that Leo extracted a resignation from Photios. In 887, Photios and his protégé,
Theodore Santabarenos, were put on trial for treason before a tribunal headed by senior officials, headed by
Andrew the Scythian. Although the sources sympathetic to Photios give the impression that the trial ended without a conviction, the chronicle of Pseudo-Symeon clearly states that Photios was banished to the monastery of Gordon, where he later died. Yet it appears that he did not remain reviled for the remainder of his life.
Photios continued his career as a writer throughout his exile, and Leo probably rehabilitated his reputation within the next few years; in his Epitaphios on his brothers, a text probably written in 888, the Emperor presents Photios favorably, portraying him as the legitimate archbishop, and the instrument of ultimate unity, an image that jars with his attitude to the patriarch in the previous year.
 Confirmation that Photios was rehabilitated comes upon his death: according to some chronicles, his body was permitted to be buried in Constantinople. In addition, according to the anti-Photian biographer of Ignatius, partisans of the ex-patriarch after his death endeavored to claim for him the "honor of sainthood". Furthermore, a leading member of Leo's court,
Leo Choirosphaktes, wrote poems commemorating the memory of several prominent contemporary figures, such as
Leo the Mathematician and the Patriarch Stephen, and he also wrote one on Photios.
 Shaun Tougher notes, however, that "yet Photios's passing does seem rather muted for a great figure of Byzantine history [...] Leo [...] certainly did not allow him back into the sphere of politics, and it is surely his absence from this arena that accounts for his quiet passing."
The Eastern Orthodox Church venerates Photios as a saint; his feast day is February 6.