deficiencies in his leadership in its later demise. John V Palaiologos succeeded his father as Byzantine emperor, but at only nine years of age, he required a regent. The energetic campaigns of emperor Andronikos III simply lacked sufficient strength to defeat the imperial enemies and led to several significant Byzantine reverses at the hands of Bulgarians, Serbians, and Ottomans. Andronikos III nevertheless provided active leadership and cooperated with able administrators. Under him, the empire came closest to regaining a position of power in the Balkans and Greek peninsula after the Fourth Crusade. The loss of a few imperial territories in Anatolia, however, left the Ottoman Turks poised to expand into Europe. Within a few months after the death of Andronikos III, controversy over the right to exercise the regency over the new emperor John V Palaiologos and the position of John Kantakouzenos as all-powerful chief minister and friend of Andronikos led to the outbreak of the destructive Byzantine civil war of 1341–47, which consumed the resources of the empire and left it in an untenable position. The weakened Byzantine Empire failed to prevent the formation of the Serbian Empire and, more ominously, the Ottoman invasion of Europe. See also List of Byzantine emperors Notes References External links Palaiologos dynasty Andronikos Palaiologos Andronikos Palaiologos Eastern Orthodox monarchs Byzantine people of Armenian descent 14th-century Byzantine emperors Byzantine people of the Byzantine–Ottoman wars People from Constantinople Sons of Byzantine emperors