Crimean Khanate
The formation period of the Crimean Tatar spoken dialects began with the first Turkic invasions of Crimea by Cumans and Pechenegs and ended during the period of the Crimean Khanate. However, the official written languages of the Crimean Khanate were Chagatai and Ottoman Turkish. After Islamization, Crimean Tatars wrote with an Arabic script.