Prior to assuming the purple, Romanos was Eparch of Constantinople. The previous emperor, Constantine VIII (the brother of Basil II) married the heir of the Macedonian dynasty, Empress Zoe, to Romanos, thus making him emperor. To gain popularity, he endowed gifts to the church and undertook expensive building projects (including restoring Blachernai). He suffered a defeat at the hands of the Emir of Aleppo in 1030. His plummeting popularity resulted in his murder: he was drowned in a bath.

Romanos restored the Aqueduct of Valens, with special attention to underground conduits and kastelloi.