As of 1920, the British had described the vilayet as being "one of the most prosperous in Anatolia." The northern and western regions were mainly occupied by Christians. Highlands were populated by Turkish immigrants from Europe. The area near the Sea of Marmara was considered the most fertile area, with a large portion of the vilayet being "marshy and fever-stricken, especially between Bursa and Panderma." The Hüdavendigâr Vilayet produced wheat, barley, maize, beans, and seeds in the northern and western regions. Throughout the region, opium, tobacco and cotton was also produced. The area around Lake Iznik produced rice. The Balıkhisar area produced "some of the finest fruit grown in Turkey." Barley is also of large production in the highlands and is exported to England.