Khalaj is a Turkic language. It is thought to be the closest language to Old Turkic. Initially, it was classified under Azerbaijan dialects due to the fact that it had similar characteristics to those dialects. However, recent studies have proved that it is not an Azerbaijan dialect. Khalaj is mainly spoken in Afghanistan and Iran. By the year 2000 there were approximately 42,000 people speaking the language. This was an increase from the 17,000 people who used to speak the language in 1968. Most Khalaj speakers are bilingual. They can speak Khalaj as well as Persian. Some Khalaj children can only speak Persian. There are 2 major Khalaj dialects. These are the northern and southern dialects. The dialectical differences are not very big.
The first possible source of information about the Khalaj language was provided by Minorsky Vladimir between 1940-1942. Vladimir published a couple of Khalaj texts. However, he did not categorize Khalaj as an independent language group. Other people who provided more information on the language includes Mohammad Moqaddam in 1950 and G. Doerfer in the 20th century, when he went for expeditions in Persia. G. Doerfer carried out an extensive research on the Khalaj language and came up with the first ever Khalaj dictionary in 1980 and a Khalaj grammar book in 1988. Another important milestone of Doerfer’s expeditions was the classification of Khalaj as an independent language group, consisting of several dialects.
Based on Zemarcos’ Syriac chronicle, Khalaj speakers are the remnants of the Hephthalites, who were a Turkic people. According to historic records, the Khalajes lived in Zabulistan, present day Afghanistan, and ruled as Zunbils. They were overthrown by the Saffarids in 879 and ruled by the Samanids and the Ghaznavids. During the time that they were ruled by the Ghaznavids, some Khalajes were gradually assimilated into the Ghilzai tribe of Afghanistan. The Khalajes eventually revolted against the Ghaznavids and overthrew them. The Khalajes were later subjugated by the Khwarezmshahs in the the 13th century. When the Mongols invaded their tetrrioty in 1221, some Khalajes sided with the Mongols. Eventually, some Khalajes went to India and served in Delhi, Bengal and western India, while others chose to remain in Afghanistan.