The first major recordings of the Khakas language originate from the middle of the 19th century. The Finnish linguist Matthias Castrén, who travelled through northern and Central Asia between 1845 and 1849, wrote a treatise on the Koybal dialect, and recorded an epic. Wilhelm Radloff traveled the southern Siberian region extensively between 1859 and 1870. The result of his research was, among others, published in his four-volume dictionary, and in his ten-volume series of Turkic texts. The second volume contains his Khakas materials, which were provided with a German translation. The ninth volume, provided with a Russian translation, was prepared by Radloff's student Katanov, who was a Sagay himself, and contains further Khakas materials.