"Byzantine Empire, 913\u2013927 war with" . "Byzantine Empire" . . "Bulgaria, 913\u2013927 war with" . . "Bulgarian Empire" . ":Byzantine\u2013Bulgarian war of 913\u2013927" . . "Byzantine\u2013Bulgarian war of 913\u2013927" . . . . "expedition against the Bulgarians" . . . . "wage a new war" . . . "ongoing war" . "War of 913\u2013927" . . "20-year-long war" . "War with Bulgaria" . "Byzantine\u2013Bulgarian war" . . . "War of 913-927" . "long war" . . "prepare for war" . "war with Bulgaria" . "Principality of Serbia" . "* Serbia annexed by Bulgaria" . . . . "Unknown" . "protracted and disastrous war" . "Second Bulgarian Empire" . "Bulgarian victory" . . . . . "921-922 campaign against Byzantium" . . "at war" . "Bulgarian-Byzantine War" . . . . . "Byzantine\u2013Bulgarian War" . "Unknown" . . "Fourth Bulgarian-Byzantine War" . "Byzantine\u2013Bulgarian war of 913\u2013927" . . "First Bulgarian Empire" . "* Byzantium recognizes the imperial title of the Bulgarian monarchs and theBulgarian Patriarchate" . . "war against the Byzantines" . . "protracted conflict" . . "bitter war" . . . .