Basil I (812-886), Byzantine emperor (867-886) and founder of the Macedonian dynasty. Born in Macedonia to a peasant family, Basil worked during his youth as a groom in the imperial stables in Constantinople (now Istanbul). He won the favor of Emperor Michael III, who made him his chamberlain. In 866 Basil became co-ruler of the Byzantine Empire with Michael and a year later had Michael assassinated. As sole ruler of the empire, Basil began the reform of the legal code completed by his son Leo VI, introduced other administrative reforms, and restored the scholar Photius to the patriarchate.