According to historian Alexander Mikaberidze, "The size of the Muslim army is still a matter of debate, with numbers ranging from a fantastic 600,000 men (as given by Walter the Chancellor and Matthew of Edessa) to 400,000 (Sempad Sparapet's Chronicle), while estimates of modern Georgian historians vary between 100,000 and 250,000 men. Although the higher numbers are exaggerated, all sources indicate that the Muslims made massive preparations and vastly outnumbered the Georgians. In mid-summer 1121, the Muslim troops advanced along various routes, with part of them passing the provinces of Erzerum and Kars, while Sultan Toghrul ibn Muhammad moved through Ganja and Tughan-Arslan the "Hunchback" marched from Dvin."(Mikaberidze, "Miraculous Victory")