The Tigrinya people (ትግርኛ, ብሄረ ትግርኛ təgrəñña), also known as Tigrigna, are an ethnic group native to Eritrea. They speak the Tigrinya language. There also exists a sizable Tigrinya community in the diaspora. One view believes that the name comes from the word tägärät (ተገረት), meaning "she ascended". The word tägäru (ተገሩ) "they ascended" describes the ascension of the earliest indigenous people to the mountainous highlands of Eritrea as the plateau's first settlers. The Tigrinya tribe were first mentioned around the 8th to 10th centuries, in which period manuscripts preserving the inscriptions of Cosmas Indicopleustes (fl. 6th century) contain notes on his writings including the mention of a tribe called Tigretes. In Eritrea the Tigrinya people are referred to as Biher-Tigrinya people or the "Kebessa" people, kebessa meaning Eritrean highlands. Both the Tigrinya and Tigre tribes in Eritrea are very close kin to the ethnic group Tigrayans in Tigray, Ethiopia. All the Tigrinyas, Tigre, and Tigrayans peoples were supposedly from the same group until the 8th century, and shared the Aksumite Kingdom before its demise. These people grew apart in lexical, societal construction and dialect from around the 9th century. Tigrayans in Tigray abandoned the declining Kingdom of Aksum and the Tigrinya people built the kingdom of Medri Bahri in Eritrea by Bahre Negasi (also known as Bahre Negash; "king of the sea" in English) with its Capital in Debarwa, Seraye. It is believed that the first ancestors of the human race migrated to other parts of the world from this area. Bob Walter discovered the oldest evidence of stone tools near the coastal areas of Eritrea. The tools are believed to be 125,000 years old. There were already people living on the Red Sea coast and Eritrean highlands from the Palaeolithic and the Neolithic ages. Tigrinya is a North Ethiopic language. It is the most widely spoken language in Eritrea, and the fourth most spoken language in Ethiopia after Amharic. Tigrinya dialects differ phonetically, lexically, and grammatically.