Late in 1028, Constantine VIII lay on his deathbed.
Wishing to secure the Macedonian dynasty, but having no son, he summoned Constantine Dalassenos from Antioch to marry his oldest daughter, Zoë.
Dalassenos, the doux of Antioch was an experienced military commander, influential patrician, and unswervingly loyal to the ruling house.
The emperor's advisors preferred not to have a strong military figure as the new emperor, and persuaded the Emperor to choose Romanos instead, as a potentially more pliable and certainly less travelled candidate.
Constantine VIII forced Romanos to divorce his wife (who was sent to a monastery) and to marry Zoë, aged 50 at the time; Romanos was 60.
The marriage took place on 12 November 1028, and three days later Constantine VIII died, leaving Romanos III as emperor.

The new emperor was eager to make his mark as a ruler, but was mostly ineffectual in his enterprises.
He idealised Marcus Aurelius, aspiring to be a new philosopher king, and similarly sought to imitate the military prowess of Trajan.
 He spent large sums on new buildings and in endowing churches and monasteries.
He endeavoured to relieve the pressure of taxation on the aristocracy, which undermined the finances of the state.
Previous emperors had attempted to control the privileges of the nobles over the common people.
 Coming from the aristocracy himself, Romanos III abandoned this policy.
This failure to stand up to the aristocrats allowed them to exploit the rural mass of landed peasantry, who increasingly fell into a condition of serfdom.
This in turn undermined the traditional recruiting base of the Byzantine army.
The combination of a reduced tax base and fewer native-born troops had long-term consequences.
As revenue declined, the subsequent impoverishment of the state weakened the military's recruitment power still further.

In 1030 he resolved to lead an army in person against the Mirdasids of Aleppo, despite their having accepted the Byzantines as overlords, with disastrous results.
The army camped at a waterless site and its scouts were ambushed.
An attack by the Byzantine cavalry was defeated.
That night Romanos held an imperial council at which the demoralised Byzantines resolved to abandon the campaign and return to Byzantine territory.
Romanos also ordered his siege engines to be burned.
On 10 August 1030 the army departed its camp and made for Antioch.
Discipline broke down in the Byzantine army, with Armenian mercenaries using the withdrawal as an opportunity to pillage the camp's stores.
The Emir of Aleppo launched an attack and the imperial army broke and fled.
Only the imperial bodyguard, the Hetaireia, held firm, but Romanos was nearly captured.
Accounts vary on the battle losses: John Skylitzes wrote that the Byzantines suffered a "terrible rout" and that some troops were killed in a chaotic stampede by their fellow soldiers, Yahya of Antioch wrote that the Byzantines suffered remarkably few casualties.
According to Yahya, two high ranking Byzantine officers were among the fatalities, and another officer was captured by the Arabs.
After this defeat the army became a "laughing-stock".

Despite his victory, the Emir of Aleppo opened negotiations and signed a treaty that made Aleppo an Imperial tributary and allowed for a Greek governor to preside over the city.
In 1032 the capture and successful defence of Edessa by George Maniakes and the sound defeat of a Saracen fleet in the Adriatic did little to restore Romanos' early popularity.

Romanos faced several conspiracies, mostly centred on his sister-in-law Theodora.
In 1029 she planned to marry the Bulgarian prince Presian and to usurp the throne.
The plot was discovered, Presian was blinded and tonsured as a monk but Theodora was not punished.
In 1031 she was implicated in another conspiracy, this time with Constantine Diogenes, the Archon of Sirmium, and was forcibly confined in the monastery of Petrion.

In a vain attempt to reduce expenditure, Romanos limited his wife's expenses, which merely exacerbated the alienation between the two.
Romanos took a mistress.
Late in 1028, Constantine VIII lay on his deathbed. Wishing to secure the Macedonian dynasty, but having no son, he summoned Constantine Dalassenos from Antioch to marry his oldest daughter, Zoë. Dalassenos, the doux of Antioch was an experienced military commander, influential patrician, and unswervingly loyal to the ruling house. The emperor's advisors preferred not to have a strong military figure as the new emperor, and persuaded the Emperor to choose Romanos instead, as a potentially more pliable and certainly less travelled candidate. Constantine VIII forced Romanos to divorce his wife (who was sent to a monastery) and to marry Zoë, aged 50 at the time; Romanos was 60. The marriage took place on 12 November 1028, and three days later Constantine VIII died, leaving Romanos III as emperor.
The new emperor was eager to make his mark as a ruler, but was mostly ineffectual in his enterprises. He idealised Marcus Aurelius, aspiring to be a new philosopher king, and similarly sought to imitate the military prowess of Trajan.  He spent large sums on new buildings and in endowing churches and monasteries. He endeavoured to relieve the pressure of taxation on the aristocracy, which undermined the finances of the state. Previous emperors had attempted to control the privileges of the nobles over the common people.  Coming from the aristocracy himself, Romanos III abandoned this policy. This failure to stand up to the aristocrats allowed them to exploit the rural mass of landed peasantry, who increasingly fell into a condition of serfdom. This in turn undermined the traditional recruiting base of the Byzantine army. The combination of a reduced tax base and fewer native-born troops had long-term consequences. As revenue declined, the subsequent impoverishment of the state weakened the military's recruitment power still further.
In 1030 he resolved to lead an army in person against the Mirdasids of Aleppo, despite their having accepted the Byzantines as overlords, with disastrous results. The army camped at a waterless site and its scouts were ambushed. An attack by the Byzantine cavalry was defeated. That night Romanos held an imperial council at which the demoralised Byzantines resolved to abandon the campaign and return to Byzantine territory. Romanos also ordered his siege engines to be burned. On 10 August 1030 the army departed its camp and made for Antioch. Discipline broke down in the Byzantine army, with Armenian mercenaries using the withdrawal as an opportunity to pillage the camp's stores. The Emir of Aleppo launched an attack and the imperial army broke and fled. Only the imperial bodyguard, the Hetaireia, held firm, but Romanos was nearly captured. Accounts vary on the battle losses: John Skylitzes wrote that the Byzantines suffered a "terrible rout" and that some troops were killed in a chaotic stampede by their fellow soldiers, Yahya of Antioch wrote that the Byzantines suffered remarkably few casualties. According to Yahya, two high ranking Byzantine officers were among the fatalities, and another officer was captured by the Arabs. After this defeat the army became a "laughing-stock".
Despite his victory, the Emir of Aleppo opened negotiations and signed a treaty that made Aleppo an Imperial tributary and allowed for a Greek governor to preside over the city. In 1032 the capture and successful defence of Edessa by George Maniakes and the sound defeat of a Saracen fleet in the Adriatic did little to restore Romanos' early popularity.
Romanos faced several conspiracies, mostly centred on his sister-in-law Theodora. In 1029 she planned to marry the Bulgarian prince Presian and to usurp the throne. The plot was discovered, Presian was blinded and tonsured as a monk but Theodora was not punished. In 1031 she was implicated in another conspiracy, this time with Constantine Diogenes, the Archon of Sirmium, and was forcibly confined in the monastery of Petrion.
In a vain attempt to reduce expenditure, Romanos limited his wife's expenses, which merely exacerbated the alienation between the two. Romanos took a mistress. 
Romanos III Argyros