The prehistory of Nubia dates to the Paleolithic around 300,000 years ago. By about 6000 BC, peoples in the region had developed an agricultural economy. They began using a system of writing relatively late in their history, when they adopted the Egyptian hieroglyphic system. Ancient history in Nubia is categorized according to the following periods: A-Group culture (3700–2800 BC), C-Group culture (2300–1600), Kerma culture (2500–1500), Nubian contemporaries of the New Kingdom (1550–1069), the Twenty-fifth Dynasty (1000–653), Napata (1000–275), Meroë (275 BC–300/350 AD), Makuria (340–1317), Nobatia (350–650), and Alodia (600s–1504).