the church of St. Sophia became one of Islam's grandest mosques. Most sultans tried to add to the city's splendor: Suleyman the Magnificent built the great Suleymaniye mosque in the sixteenth century. Constantinople became the commercial center dealing in products from Asia, Africa, and Europe. Many urban inhabitants belonged to merchant and artisan classes. The government closely regulated both activities. Artisan guilds were very important. By the seventeenth century, the Turkish language became the preferred vehicle for literature and government. The Ottomans left a significant artistic legacy in poetry, ceramics, carpet manufacturing, and architecture.