Alexios has lost much of his popularity during the last twenty years of his life.
The years have been marked by persecution of the followers of the Paulician and Bogomil heresies—one of his last acts is to publicly burn at the stake Basil, a Bogomil leader, with whom he had engaged in a theological dispute.
Basil had first come to the attention of the emperor after imperial officers had tortured a member of the Bogomil sect to reveal the identity of their leader.
He admitted that Basil was their leader and that he had selected twelve teachers to act as his apostles.
This sect, noted for their Manichaean tendencies, iconoclastic principles and their detestation of the Orthodox hierarchy, has been rapidly gaining adherents throughout Alexius’ reign, and has begun to cause alarm among the Orthodox clergy.
Despite the success of the crusade, Alexios had also had to repel numerous attempts on his territory by the Seljuqs in 1110–1117.
Alexios was for many years under the strong influence of an eminence grise, his mother Anna Dalassene, a wise and immensely able politician whom, in a uniquely irregular fashion, he had crowned as Augusta instead of the rightful claimant to the title, his wife Irene Doukaina.
Dalassena had been the effective administrator of the Empire during Alexios' long absences in military campaigns: she was constantly at odds with her daughter-in-law and had assumed total responsibility for the upbringing and education of her granddaughter Anna Komnene.
Alexios' last years have also been troubled by anxieties over the succession.
Although he had crowned his son John II Komnenos co-emperor at the age of five in 1092, John's mother Irene Doukaina wishes to alter the succession in favor of her daughter Anna and Anna's husband, Nikephoros Bryennios the Younger.
Bryennios had been made kaisar (Caesar) and received the newly created title of panhypersebastos ("honored above all"), and has remained loyal to both Alexios and John.
Nevertheless, the intrigues of Irene and Anna disturb even Alexios' dying hours.
The emperor dies on August 15, 1118, and his son succeeds him as John II.
In conspiring to depose her brother, Anna is unable to obtain the support of her husband and the plot is discovered.
Nikephoros had refused to enter into the conspiracy set afoot by his mother-in-law and his wife Anna to depose John and raise himself to the throne.
His wife attributes his refusal to cowardice, but it seems from certain passages in his own work that he really regarded it as a crime to revolt against the rightful heir; the only reproach that can be brought against him is that he did not nip the conspiracy in the bud.
Anna forfeits her property, retiring to a convent, where she begins work on the Alexiad, a history of the life and reign of her father.
