of 2018, Eswatini has the 12th-lowest life expectancy in the world, at 58 years. The population of Eswatini is young. As of 2018, people aged 14 years or younger constitute 35% of the country's population and the median age is 22 years. History Artefacts have been found indicating human activity dating back to the early Stone Age, around 200,000 years ago. Prehistoric rock art paintings dating from as far back as c. 27,000 years ago to as recently as the 19th century can be found around the country. The earliest known inhabitants of the region were Khoisan hunter-gatherers. They were largely replaced by the Nguni during the great Bantu migrations. These peoples originated from the Great Lakes region of eastern and central Africa. Evidence of agriculture and iron use dates from about the 4th century. People speaking languages ancestral to the current Sotho and Nguni languages began settling no later than the 11th century. Swazi settlers (18th and 19th centuries) The Swazi settlers, then known as the Ngwane (or bakaNgwane) before entering Eswatini, had been settled on the banks of the Pongola River. Before that, they were settled in the area of the Tembe River near present-day Maputo, Mozambique. Continuing conflict with the Ndwandwe people pushed them further north, with Ngwane III establishing his capital at Shiselweni at the foot of the Mhlosheni hills. Under Sobhuza I, the Ngwane people established their capital at Zombodze in the heartland of present-day Eswatini. In this process, they conquered and incorporated the long established clans of the country known to the Swazi as Emakhandzambili (those found ahead). Eswatini derives its name from a later king named Mswati II. KaNgwane, named for Ngwane III, is an alternative name for Eswatini, the surname of whose royal house remains Nkhosi Dlamini. Nkhosi literally means "king". Mswati II was the greatest of the fighting kings of Eswatini, and he greatly extended the area of the country to twice its current size. The Emakhandzambili clans were initially incorporated into the kingdom with wide autonomy, often including grants of special ritual and political status. The extent of their autonomy, however, was drastically curtailed by Mswati, who attacked and subdued some of them in the 1850s. With his power, Mswati greatly reduced the influence of the Emakhandzambili while incorporating more people into his kingdom either through conquest or by giving them refuge. These later arrivals became known to the Swazis