Nikephoros III Botaneiates, Latinized as Nicephorus III Botaniates (Greek: Νικηφόρος Βοτανειάτης, c. 1002 – 10 December 1081), was Byzantine emperor from 1078 to 1081. He belonged to a family claiming descent from the Byzantine Phokas family.
Nikephoros Botaneiates had served as general from the reign of Constantine IX. Drawn to politics, he had been an active participant in the uprising that brought Isaac I to the throne in 1057, including a prominent role in the Battle of Petroe. Although considered a competent general, he had suffered a number of humiliating setbacks throughout his career. In 1064, he, together with Basil Apokapes, doux of Paradounavon, defended the Balkan frontiers against the invading Oghuz Turks, but was defeated and suffered the humiliation of being taken captive. The outbreak of an epidemic soon began decimating the Turks, however, and the prisoners were recovered, while the survivors were quickly recruited in the Byzantine army.
In 1067, Nikephoros had been considered as a possible husband for the empress Eudokia Makrembolitissa, widowed wife of Constantine X, but she eventually set her heart on Romanos IV Diogenes. Excluded from Romanos's campaign at Manzikert, he retired to his estates in Anatolia. Eventually, under Michael VII Doukas, he became strategos of the Anatolic theme and commander of the troops in Asia Minor. Here he participated in the shambolic acts that crippled the empire’s eastern provinces, including his strategic retreat when Caesar John Doukas was confronting Norman mercenary rebels, resulting in the humiliating defeat of the Byzantine army and the capture of John Doukas.
In 1078 he revolted against Michael VII and his finance minister Nikephoritzes. With the support of the Seljuk Turks, who provided him with valuable troops, he marched upon Nicaea, where he proclaimed himself emperor. In the face of another rebellious general, Nikephoros Bryennios, his election was ratified by the aristocracy and clergy, while Michael VII abdicated and became a monk. On 24 March 1078, Nikephoros III Botaneiates entered Constantinople in triumph and was crowned by Patriarch Kosmas I of Constantinople. With the help of his general Alexios Komnenos, he defeated Bryennios and other rivals but failed to clear the invading Turks out of Asia Minor.
To solidify his position after the death of his second wife, Nikephoros III sought to marry Eudokia Makrembolitissa, the mother of Michael VII and the widow of Constantine X and Romanos IV. This plan was undermined by the Caesar John Doukas, and Nikephoros instead married Maria of Alania, in contravention of church canons, as Maria was still the wife of Michael VII, who had entered the monastery of Stoudios. Nevertheless, Nikephoros did not recognize the succession rights of Maria's son Constantine Doukas, while his plan to promote his worthless nephew Nikephoros Synadenos as co-emperor exposed him to the suspicion and plots of the surviving portions of the Doukas faction at court. Nikephoros' administration did not win him much support, as his favored courtiers alienated much of the older court bureaucracy and failed to stop the devaluation of the Byzantine currency.
Uprisings began almost immediately. Apart from the discontent of the Byzantine aristocracy, several Armenian princes in Asia Minor attempted to establish their independence from the empire. Two Paulician leaders launched their own rebellion in Thrace, in a brutal religious conflict that was not easily suppressed. Consequently, Nikephoros became increasingly dependent on the support of Alexios Komnenos, who successfully defeated the rebellion of Nikephoros Basilakes in the Balkans (1079) and was charged with containing that of Nikephoros Melissenos in Anatolia (1080). The Byzantine Empire also faced foreign invasion, as the Norman Duke Robert Guiscard of Apulia declared war under the pretext of defending the rights of young Constantine Doukas, who had been engaged to Robert's daughter Helena. As Alexios was entrusted with substantial armed forces to combat the impending Norman invasion, the Doukas faction, led by the Caesar John, conspired to overthrow Nikephoros and replace him with Alexios. Failing to secure the support of either the Seljuk Turks or Nikephoros Melissenos (both parties being his traditional enemies), Nikephoros III was forced to abdicate in favour of the Komnenos dynasty, to which he was connected through the engagement of his grandson to the daughter of Alexios's older brother Manuel. The deposed emperor retired into the monastery he had endowed at the Church of St. Mary Peribleptos, where he died later the same year.