Map of the Byzantine Empire 1350 AD

Despite occasional periods of recovery, the Byzantine Empire was in terminal political decline by the middle of the 14th Century. A bitter civil war, which saw the Ottoman Turks become intimately involved in Byzantine affairs for the first time, was coupled with the outbreak of bubonic plague in 1349, as well as a general failure in the dying Empire's financial and military resources.

The Empire's main possessions were now restricted to Thrace, Thessalonika, the Peloponnese, and Constantinople itself.