constantine was also a cousin of eudokia makrembolitissa, who married isaac's lieutenant and successor as emperor, constantine x doukas, as she too is referred to as a niece of the patriarch. in 1067, constantine x was dying. eudokia, as empress-dowager and mother of constantine's under-age sons, would lead the regency, but constantine x feared that she might well include her relatives, who already held high posts in court, in the regency, thus posing a potential threat to the succession of constantine x's own children. he therefore had eudokia swear publicly that she would not remarry nor appoint any co-regents over her under-age sons with constantine other than the latter's brother john doukas, an oath that she would soon break, however, with her marriage to romanos iv diogenes.