The fortified citadel of Didymoteicho in Greek Thrace figured prominently in Late Byzantine history. It had been an imperial residence and a major military and administrative center since the mid-13th century, and throughout the remainder of its Byzantine history, it maintained close relations with Constantinople. Andronicus III resided in Didymoteicho during the 1320s, prior to his accession to the throne in 1328. With the proclamation of John VI Cantacuzenus as emperor in Didymoteicho in 1341, the city became his de facto capital, from which he launched his disastrous civil war.