Little is known of Nicetas' life. He was appointed [[patriarch]] by the iconoclast emperor [[Constantine V]] to replace Patr. [[Constantine II of Constantinople|Constantine II]], an iconoclast patriarch whom the emperor had placed of on the patriarchal throne but who apparently had turned against the emperor in June 766 and joined the [[iconodule|iconophiles]]. Patr. Constantine II was [[deposition|deposed]], imprisoned, and tortured before he was beheaded.