Aided by the Avars and the Bulgars, the Slavic tribes started in the 6th century a gradual invasion into the Byzantine lands.

His letters show him laying claim to a vast array of lands around Austrasia, including Byzantine lands.

The Byzantine lands had been a stable Christian state since the 4th century, though had been in a crisis immediately before the Fourth Crusade.

After consolidating his rule he launched an attack against the Byzantine lands to the south.

The crusaders established the Latin Empire (1204-1261) and other "Latin" states in the Byzantine lands they conquered.

Immediately upon his accession to the throne he attacked Byzantine lands in Macedonia.

The Byzantines were initially defeated near Adrianople but went on to score a victory, after which the Slavs left Byzantine lands.

While Byzantine land was being divided, there was no one in control of the seas, so pirates raided towns on many of the islands.

Some chose to stay, while others went to Byzantine lands.

Sclaveni was the term for Slavic allies settled in Byzantine lands, in the administrative regions of Sclaviniae.