David Nicolle & Mikhail Zhirohov 
Khazars [PDF ebook] 
A Judeo-Turkish Empire on the Steppes, 7th 11th Centuries AD

The Khazars were one of the most important Turkic peoples in European history, dominating vast areas of southeastern Europe and the western reaches of the Central Asian steppes from the 4th to the 11th centuries AD. They were also unique in that their aristocratic and military elites converted to Judaism, creating what would be territorially the largest Jewish-ruled state in world history. They became significant allies of the Byzantine Empire, blocking the advance of Islam north of the Caucasus Mountains for several hundred years. They also achieved a remarkable level of metal-working technology, and their military elite wore forms of iron plate armour that would not be seen in Western Europe until the 14th century. The Khazar state provided the foundations upon which medieval Russia and modern Ukraine were built. Fully illustrated with detailed colour plates, this is a fascinating study into the armies, organisation, armour, weapons and fortifications of the Khazars.