By withholding the tribute which Irene had agreed to pay to Harun al-Rashid, Nicephorus committed himself to a war with the Saracens.
By the death of Harun in 809, Nicephorus was left free to deal with the Bulgarian king, Krum, who was harassing his northern frontiers.
815), the son and successor ci Harun al-Rashid, caused an Arabic version of Ptolemy's great astronomical work (rat, meyio-Tf) to be made, which is known as the Almagest, the word being nothing more than the Gr.
Half a day's journey beyond Sura, on the Mesopotamian side of the river, are the extensive ruins of Haragla (Heraclea) and Rakka, once the capital of Harun al-Rashid (Nicephorium of Alexander; Callinicus of the Seleucids and Romans).
Already under Charlemagne this development is noticeable; in his generous treatment of the Jews this Christian emperor stood in marked contrast to his contemporary the caliph Harun al-Rashid, who persecuted Jews and Christians with equal vigour.