[3] Whatever his exact ancestry, he shared ethnic and geographical origin with the Emperor Basil I the Macedonian, a factor that probably played an important role in his ascent to high office during the latter's reign.
[2] In late 882, the young Leo, Basil's second son and heir after the death of his elder brother Constantine in 879, was wedded to Theophano, a member of the Martinakes family.
The bride was the choice of empress Eudokia Ingerina, and did not please Leo, who instead preferred the company of Zoe Zaoutzaina, the beautiful daughter of Stylianos Zaoutzes.
[4] At that point, Zaoutzes held the post of mikros hetaireiarches, i.e. commander of the junior regiment of the Byzantine emperor's mercenary bodyguard, the hetaireia.
[9] Upon Basil's death, Leo was crowned emperor, but Zaoutzes, who was awarded the titles of patrikios and magistros and the office of logothetes tou dromou, effectively assumed control of the government, directing state policy.
[1] One tradition, based on the Vita Euthymii (the hagiography of Patriarch Euthymios I), holds that Basil himself appointed Zaoutzes as regent (epitropos), but other sources indicate that his ascent to power was more gradual.
[10] It is indicative of his authority that most of Leo's ordinances (novels) are directed to him in person, and in 893, he succeeded in getting his protégé, Antony Kauleas, elected as Patriarch of Constantinople.
However, although Zaoutzes has traditionally been regarded as an all-powerful regent over a weak emperor, in no small part due to the account provided in the Vita Euthymii, the actual relationship between the two may have been quite different.
A more careful evaluation of the source material has led modern scholarship to conclude that Leo was actively involved in government, and that Zaoutzes as chief minister was loyal and obsequious to his master.
Of the few available sources on his career, the Vita Euthymii, compiled years after Zaoutzes's death, is extremely hostile, seeking to pin the responsibility for several of the reign's failures or unpopular decisions on him, and thus preserve Leo from blame.