The Khazar Correspondence is a set of documents, which are alleged to date from the 950s or 960s, and to be letters between Hasdai ibn Shaprut, foreign secretary to the Caliph of Cordoba, and Joseph Khagan of the Khazars. The Correspondence is one of only a few documents attributed to a Khazar author, and potentially one of only a small number of primary sources on Khazar history. The authenticity of the correspondence has been challenged, on the grounds that it has little in common with the otherwise attested chronology, language, borders and economy of the Khazars at the time.