ABBASÎ HALİFESİ HÂRÛNU’R-REŞÎD’İN İSTANBUL SEFERİ VE BU SEFER ESNASINDA İZLEMİŞ OLDUĞU GÜZERGÂHLAR (THE EXPEDITION OF THE ABBASID CALIPH HARUN AL-RASHID TO CONSTANTINOPLE AND THE COURSES ORBITTED DURING THIS EXPEDITION) - ABDULHALİK BAKIR - | Cappadocia Journal of History and Social Sciences