Actually Theophano married him in a hurry after the sudden death of Romanus II... Praepositus Iosif Bringas (who was a eunuch and couldnt claim the throne for himself) was trying to usurp the Crown for his brother... Theophano needed a superb (and popular) General to protect her and her infant children... Nicephorus was recalled from Syria and was smart enough to bring his army with him... Nicephorus wasnt planning to be crowned Emperor in the first place... He would act as guardian for the infant co-Emperors Basil II and Constantine VII and then stepped down... But alas he was seduced by the young widow Empress and was pressed by the army to accept the crown...