water wells. There is a square where on market days huge numbers of slaves are sold, both male and female. A young girl of fifteen is worth about six ducats, and a young man almost as much; small children are worth about half as much as grown slaves. Towards the end of the 16th century, Gao controlled an empire that extended for over 1,400,000 km2, an area comparable in size to the modern state of Mali. The Tarikh al-fattash reports that a survey conducted during the reign of Askiya Al-Hajj (1582–1586) found that there were 7,626 houses without counting the huts made of straw. Assuming each house was occupied by an average of 6 people, this would imply a population of around 45,000. The Moroccan invasion of 1591 led to the collapse of the Songhai Empire. The invaders chose to make Timbuktu their capital and the importance of Gao declined. The German explorer Heinrich Barth visited Gao in 1854 on his return journey from Timbuktu. He found a village of about 300 huts constructed of matting and grouped in clusters. The inhabitants were very poor and had only a few boats as they lacked wood for their construction. The site of the ancient town was overgrown with Capparis decidua bushes. 21st century On 31 March 2012, one day after the capture of Kidal, Malian military forces retreated from Gao's military bases, allowing it to be occupied by Tuareg rebellion member groups MNLA and Ancar Dine. Timbuktu was captured the following day. On 6 April, the MNLA declared the region independent of Mali as the nation of Azawad. After the Battle of Gao on 26 and 27 June 2012, the MNLA lost control to Islamist militias. After the 2012 rebellion forced the Malian Army out of Gao and the state of Azawad was proclaimed, the National Movement for the Liberation of Azawad took control of the governor's building, flying the flag of Azawad over it and rechristening it the Palace of Azawad. On 26 June 2012, the tension came to all-out combat in Gao between the MNLA and MOJWA, with both sides firing heavy weapons. MNLA Secretary General Bilal ag Acherif was wounded in the battle. The MNLA were soon driven from the city, and from Kidal and Timbuktu shortly after. However, the MNLA stated that it continued to maintain forces and control some rural areas in the region. The following