Anna Dalassene was the daughter of Alexios Charon, a Byzantine official in southern Italy and unknown woman who was a granddaughter of the Byzantine aristocrat, Theophylact Dalassenos. Sometime between 1040 and 1045, Anna married Iōannēs Komnēnos, the son of the late Byzantine general, Manouēl Erōtikos Komnēnos. Anna and Iōannēs had eight children, five sons and three daughters. In 1057, Iōannēs’ brother, Isaakios Komnēnos, led a rebellion against the emperor, Mikhaēl VI Bringas. On the advice of the Ecumenical Patriarch of Constantinople, Mikhaēl abdicated on 31 August 1057 and became a monk and Isaakios became the new emperor.
However, Isaakios’ reign was short: he clashed with the Patriarch, Mikhaēl Keroularios, over confiscation of church property. Their quarrel ended with the deposition of Keroularios and Isaakios abdicating and entering a monastery. The imperial crown then passed to Kōnstantinos X Doukas, who was married Eudokia Makrembolitissa, the late Patriarch’s niece. Kōnstantinos’ reign proved inglorious and unpopular: he undid most of Isaakios’ military reforms and went on to lose southern Italy to the Hauteville brothers. Iōannēs and Kōnstantinos both died in 1067, but Anna took care to strengthen her family’s political position by arranging marriages with top political families. With Kōnstantinos’ death, the throne was taken by Rōmanós IV Diogénēs, who had married the widowed Eudokia Makrembolitissa, who Anna politically supported against the Doukai.
Unfortunately, Rōmanós was defeated and captured by the Seljuk Turks after the Battle of Manizkert on 19 August 1071. The Caesar Iōannēs Doukas took advantage of the situation to promote his nephew, Mikhaēl VII Doukas, the son of the late Kōnstantinos. After Rōmanós was released from captivity, Iōannēs Doukas ordered that his blinding. Anna remained secretly hostile to the Doukai, but consented to the marriage of her second surviving son, Alexios, to Iōannēs Doukas’ granddaughter, Eirēnē Doukaina. Young Mikhaēl VII proved to be as incompetent as his father, unable to do anything about the Normans, Bulgarians, or Seljuk Turks. In 1078, in response to two rebellions, Mikhaēl abdicated and Nikephoros III Botaneiates became the new emperor and married Maria of Alania, the wife of Botaneiates who had previously been married to Mikhaēl VII. Botaneiates intended to be succeeded by one of his relatives, but Maria wished for the accession of her son by Mikhaēl, Kōnstantinos Doukas and entered into an alliance with Anna; thus Maria agreed to adopt Anna’s son, Alexios, as her her own.
In February of 1081, Alexios and his older brother, Isaakios, fled Constantinople to raise an army while Anna took refuge in the Haghia Sophia. Botaneiates suspected a plot, but Anna denied it. On 1 April 1081, Alexios and Isaakios entered Constantinople with an army and forced Botaneiates to abdicate. Alexios thus became emperor and appointed young Kōnstantinos Doukas as his co-emperor. Anna then attempted to convince Alexios to divorce Eirēnē Doukaina and marry Maria of Alania instead, but found herself blocked by the Doukai and the Patriarch, Kosmas. In the end, Eirēnē remained as Alexios’ wife, but Anna exercised far more authority at court than her daughter-in-law did and she and Maria of Alania took on the full responsibility of educating Anna’s first granddaughter and namesake, Anna Porphyrogénnētē Komnēnē.
The date of Anna’s retirement from court and the circumstances surrounding it are unclear, though it was after the First Crusade first passed through the city. Either way, it is known that Anna died on 1 November of 1100 or 1102.