The city of Kano was founded around A.D. 1000 as an Hausa city of its own. Kano remained a big emirate, or Muslim kingdom, until the birth of the country, Nigeria, in 1903. Kano became known for its trade in gold, leather, ivory, salt and slaves within the area. This perhaps is the reason for the city's wealth and power in the 14th century, when Islam gained a growing following. By the 15th century, the first Central Mosque had been built in the city.