This book, now back in print having been unavailable for many years, is one of the most important contributions to Turkic and Mongolic linguistics, and to the contentious 'Altaic theory'. Proponents of the theory hold that Turkish is part of the Altaic family, and that Turkish accordingly exists in parallel with Mongolic and Tungusic-Manchu. Whatever the truth of this theory, Gerard Clauson's erudite and vigorously expressed views, based as they were on a remarkable knowledge of the lexicon of the Altaic languages and his outstanding work in the field of Turkish lexicography, continues to command respect and deserve attention.

Mirza Mahdi Xan Astarabadi came from a Persian bureaucratic family. He had for a time served Hadir Shah (r. 1736-1747) as Chief Secretary and wrote two ornate histories of his master's eventful reign. The present work was written in or near 1759 as a product of his retirement. Sanglax, meaning Stony place, begins with a grammar of the variety of Turkish which achieved the status of a literary language in Eastern Iran and the adjoining regions of Central Asia in the 15th and 16th centuries and is known as Cagatay but the bulk of the work consists of a Turkish-Persian dictionary.