quantitative (i.e., syllabic) verse, as opposed to the qualitative verse employed in the written poetic tradition; the basic structural unit of folk poetry became the quatrain (Azerbaijani: dördmisralı) rather than the couplets (Azerbaijani: beyt) more commonly employed in written poetry. Furthermore, Azerbaijani folk poetry has always had an intimate connection with song—most of the poetry was, in fact, expressly composed so as to be sung—and so became to a great extent inseparable from the tradition of Azerbaijani folk music. In contrast to the tradition of Azerbaijani folk literature tended to embrace the influence of Persian and Arabic literature. To some extent, this can be seen as far back as the Seljuk period in the late 11th to early 14th centuries, where official business was conducted in the Persian language, rather than in Turkic, and where a court poet such as Dehhanî—who served under the 13th century sultan Ala ad-Din Kay Qubadh I—wrote in a language highly inflected with Persian. With the founding of Safavid Iran in the 16th century, it continued this tradition. The standard poetic forms—for poetry was as much the dominant genre in the written tradition as in the folk tradition—were derived either directly from the Persian literary tradition (the qəzəl غزل; the məsnəvî مثنوی), or indirectly through Persian from the Arabic (the qəsîde قصيده). However, the decision to adopt these poetic forms wholesale led to two important further consequences: the poetic meters (Azerbaijani: aruz) of Persian poetry were adopted; Persian- and Arabic-based words were brought into the Azerbaijani language in great numbers, as Turkic words rarely worked well within the system of Persian poetic meter. This style of writing under Persian and Arabic influence came to be known as "Divan literature" (Azerbaijani: divan ədəbiyatı), dîvân (ديوان) being the Azerbaijani word referring to the collected works of a poet. Azerbaijani folk literature Azerbaijani folk literature is an oral tradition deeply rooted, in its form, in Central Asian nomadic traditions. However, in its themes, Azerbaijani folk literature reflects the problems peculiar to a settling (or settled) people who have abandoned the nomadic lifestyle. One example of this is the series of folktales surrounding the figure of Keloğlan, a young boy beset with the difficulties of finding a wife, helping his mother to keep the family house intact, and dealing with the problems caused by his neighbors. Another example is the rather mysterious figure of Nasreddin, a trickster who often