Anna Dalassena was an important Byzantine noblewoman who rose to position comparable to that of an Empress-Mother during the reign of her son Alexios I Komnenos. She married Johannes Komnenos, a nephew of Emperor Isaac I Komnenos (Emperor from 1057 to 1059). Her younger son Alexios I Komnenos rose to the throne after vicissitudes of politics. Alexius was for many years under the strong influence of her éminence grise. Wikipedia
The definitive Wikipedia entry for Anna Dalassena. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Anna_Dalassena