 The Continuation of the Chronicle by Friar George , which was written in the middle of the 10th century , recorded the first historical event – an alliance between the Magyars and the Bulgarians in the late 830s – that can without doubt be connected to the Magyars . The Byzantine Emperor Leo the Wise 's Tactics , a book written around 904 , contained a detailed description of their military strategies and way of life . Emperor Constantine Porphyrogenitus 's De administrando imperio ( " On Governing the Empire " ) , which was completed between 948 and 952 , preserves most information on the Magyars ' early history . Al @-@ Jayhani , the minister of Nasr II , ruler of the Samanid Empire , collected the reports of merchants who had traveled in the western regions of the Eurasian steppes in the 870s and 880s . Although Al @-@ Jayhani 's work was lost , later Muslim scholars Ibn Rusta , Gardizi , Abu Tahir <unk> , and Al @-@ Bakri used his book , preserving important facts about the late 9th @-@ century Magyars . However , their works also contain interpolations from later periods . Among the sources written in Western Europe , the longer version of the Annals of Salzburg , Regino of Prüm 's Chronicon , the Annals of Fulda , and Liutprand of Cremona 's <unk> ( " Retribution " ) , provide contemporaneous or near @-@ contemporaneous information of the 9th @-@ century Magyars . There are also references to the Magyars dwelling in the Pontic steppes in the legends of Cyril , Methodius and other early Slavic saints . According to historian András Róna @-@ Tas , information preserved in the Russian Primary Chronicle , which was completed in the 1110s , has to be " treated with extreme caution " . 
