cursive style of Arabic calligraphy developed during the reign of the early Ottoman Turks (16th–early 17th century). It was invented by Housam Roumi and reached its height of popularity under Süleyman I the Magnificent (1520–66). As decorative as it was communicative, dīwānī was distinguished by the complexity of the line within the letter and the close juxtaposition of the letters within the word.