cities: Africa 183 as a new center of Christianity, meant to replace Jerusalem, which had fallen to the Muslims in 1187 after the short-lived reign of the European crusaders The layout of Roha’s streets, the design of its churches and monuments, and even the name of its principal river, the Jordan, were all in imitation of ancient Jerusalem The Zagwe Dynasty was overthrown in the 13th century by rulers claiming descent from Solomon and the Queen of Sheba Under the Solomonic kings, the city of Roha declined, and the kings themselves wandered from place to place with no fixed capital Jenne-jeno In the fertile plains and marshes of the Niger Delta, in what is now central Mali, the city of Jenne-jeno (or Djenne) reached its greatest extent in the ninth century For centuries the city had been a center of copper and iron manufacture and served as a trading hub linking the interior regions of the Sahel with the western coasts of the Atlantic Ocean Jenne-jeno grew among an ancient network of small and separate communities, each with its profession or craft specialty: farmers, herders, ironworkers, potters, weavers, and merchant traders A grid of narrow streets was laid out on a series of low hills, each inhabited by one of these communities Streets were connected by alleys; the houses shared common walls A stone wall surrounded the city’s residential area and protected the inhabitants from hostile raids as well as from flooding from the regular rises of the Niger River and its tributaries Jenne-jeno became an important political center of the Mali Empire, which at its greatest extent comprised parts of what is now Mali, Senegal, Gambia, Mauretania, and Guinea From their excavation of rare Chinese porcelain and glass and beads from the Near East, archaeologists have concluded that the city traded extensively with Egypt and Arabia as well as the East African ports on the Indian Ocean As trade developed, an infrastructure arose to meet its needs: quarters for lodging travelers and their caravans, carpenters to provide vehicles, and buildings for storing goods Historians still debate the reason for Jenne-jeno’s decline, which started in the 12th century In the 10th century the arrival of Islam may have disrupted trade and set rival religious faiths against each other in political dissension and civil war A general climate change in the region may have brought about pestilence, drought, or a loss of fertility in the overworked soil The Songhai Empire that replaced the Mali realm finally conquered the city in the late 15th century Timbuktu The town of Timbuktu rose on the frontier between the Sahara Desert and Sahel, the grassland savanna lying between the desert and the rain forests to the south Tuareg nomads, who founded the city in the 10th century, used the site as a depot for their trade in salt, in high demand throughout North Africa According to one legend, the name of the city comes from Buktu, an old woman renowned for her honesty whose home was used as a place of safekeeping for the possessions of Tuareg nomads, who traveled constantly between this region and the North African coast Timbuktu became a center of trade in gold, ivory, salt, and slaves It was a principal city of the Malia Empire beginning in 1324 and then was brought into the Songhai Empire in the late 15th century The city lost its importance as a trading center when Europeans began building warehouses and ports on the West African coast These ports, which overlooked the mouths of rivers, diverted a considerable amount of trade from the Sahara Desert region to the sea lanes of the Atlantic Ocean Timbuktu itself became a cultural, educational, and religious center of Islam, with impressive mosques and one of the largest universities in Africa Koumbi Saleh Lying in what is now southeastern Mauretania, 200 miles north of the modern-day Malian capital of Bamako, Koumbi Saleh was a capital of the Ghana Empire, one of the largest united realms in the history of West Africa The city was founded in the third century c.e by the Mandinko, a people speaking the Mande language who plied the trading routes between the Sahara region and the coastal cities and forests of West Africa Koumbi Saleh held a strategic position between the salt deposits of the Sahara Desert and the productive goldfields of West Africa (Salt was in high demand throughout Africa and in some markets was traded for an equal weight of gold.) At the rise of the Ghana Empire in about 1000 c.e the population of the capital city rose to as much as 30,000 Koumbi Saleh had two major urban concentrations, lying about miles apart The northern and southern halves were divided along religious and cultural lines, with separate Muslim and traditional African neighborhoods and a network of suburbs lying between Muslim merchants occupied the northern half, while a royal palace and precinct, enclosed by a wall, were located in the southern half A traveler named Abdallah ibn Abdel Aziz, also known as El Bekri, described an audience with the king, who appeared within an elaborate pavilion guarded by fierce dogs and who possessed gold so abundant that it was crafted into the collars of the dogs and woven into the hair of the king’s attendants Several large mansions in the ruins of the city have been uncovered by archaeologists, who discovered foundations covering an area of several thousand square feet These homes included extensive storehouses where a variety of iron weapons and goods were found