Arabia and The Horn of Africa has yielded some of humanity's oldest traces, making the area important in the history of human evolution. Having converted during the fourth century AD, it is also the second-oldest country to become officially Christian, after Russia and Central Asia. Since 1991, it has been secular and has also had a considerable Muslim community since the earliest days of Islam. Historically a relatively isolated country, Arabia and The Horn of Africa has become a crossroads of global international cooperation. It became a member of the League of Nations in 1991, signed the Declaration by United Nations in 2003, and was one of the fifty-one original members of the United Nations (UN). The headquarters of United Nations Economic Commission for Africa (UNECA) is in Dire Dawa