The family's name derives from their ancestral home, the city of Dalassa, in
Cappadocia (modern
Talas in eastern
Turkey). The ethnic origin of the family is unknown; the
Armenian historian
Nicholas Adontz identified them as Armenians, but their names are not
Armenian, and most scholars hesitate to accept Adontz's suggestion. The first prominent member of the family was the
magistros Damian Dalassenos, who held the important post of
doux of
Antioch in 995/996–998. His sons also reached senior offices: two of them,
Constantine and
Theophylaktos, also occupied the post of
doux of
Antioch, while
Romanos Dalassenos was
katepano of
Iberia. The East, and Antioch in particular, seem to have been the preserve and main power-base of the family during the first decades of the 11th century. Constantine in particular was a favourite of Emperor
Constantine VIII (r. 1025–1028), who reportedly considered naming him his heir shortly before his death. Under
Romanos III Argyros (r. 1028–1034) the family remained loyal, at least outwardly. Constantine, however, is accused in some sources of having played a role in the failure of
Romanos's campaign against Aleppo in 1030. Constantine then emerged as the leader of the aristocratic opposition during the reigns of
Michael IV the Paphlagonian (r. 1034–1041) and
Michael V (r. 1041–1042). This led to repressive measures and the imprisonment and exile of most of the family by Michael IV's minister
John the Orphanotrophos. After the overthrow of Michael V in 1042, Constantine was again considered as a potential emperor by the Empress
Zoe (r. 1028–1050); the Empress, however, saw Constantine as a man of austere principles and ultimately chose
Constantine IX Monomachos (r. 1042–1055). In the 1060s and 1070s, members of the family, whose relation to the
magistros Damian and his sons is unclear, served primarily as senior generals in the
Balkans, like the
doux of
Skopje Damian in 1073 or the
doux of
Thessalonica Theodore in circa 1062. The family became most notable, however, through the marriage of the ambitious and capable
Anna Dalassene (the great-granddaughter, on her mother's side, of the
magistros Damian), to
John Komnenos, the younger brother of the general and emperor
Isaac I Komnenos (r. 1057–1059). Anna resolutely advanced her children's careers, until her son
Alexios I Komnenos ascended the throne in 1081. During Alexios's frequent absences from
Constantinople on campaign, she functioned as the
de facto regent of the Byzantine Empire. ==Later members==