Sumer
Sumer () is the earliest known civilization in the historical region of southern Mesopotamia, modern-day southern Iraq, during the Chalcolithic and Early Bronze ages, and one of the first civilizations in the world along with Ancient Egypt and the Indus Valley. Living along the valleys of the Tigris and Euphrates, Sumerian farmers were able to grow an abundance of grain and other crops, the surplus of which enabled them to settle in one place. Prehistoric proto-writing dates back before 3000 BC. The earliest texts, from c. 3300 BC, come from the cities of Uruk and Jemdet Nasr; early cuneiform script emerged around 3000 BC.
Celts
The Proto-Celtic language is usually dated to the Late Bronze Age. The earliest records of a Celtic language are the Lepontic inscriptions of Cisalpine Gaul (Northern Italy), the oldest of which predate the La Tène period. Other early inscriptions, appearing from the early La Tène period in the area of Massilia, are in Gaulish, which was written in the Greek alphabet until the Roman conquest. Celtiberian inscriptions, using their own Iberian script, appear later, after about 200 BC. Evidence of Insular Celtic is available only from about 400 AD, in the form of Primitive Irish Ogham inscriptions.