East Frisia or Eastern Friesland (German: Ostfriesland; East Frisian Low Saxon: Oostfreesland; Dutch: Oost-Friesland) is a coastal region in the northwest of the German federal state of Lower Saxony. It is the middle section of Frisia between West Frisia in the Netherlands and North Frisia in Schleswig-Holstein.
Administratively Ostfriesland belongs to three districts, namely Aurich, Leer, Wittmund and to the city of Emden. There are 465,000 people living in an area of 3,144.26 square kilometres.
There is a chain of islands off the coast, called the East Frisian Islands (Ostfriesische Inseln). These islands are (from west to east) Borkum, Juist, Norderney, Baltrum, Langeoog, Spiekeroog and Wangerooge.
The geographical region of East Frisia was inhabited in Paleolithic times by reindeer hunters of the Hamburg culture. Later there were Mesolithic and Neolithic settlements of various cultures. The period after prehistory can only be reconstructed from archaeological evidence. Access to the early history of East Frisia is possible in part through archaeology and in part through the studying of external sources such as Roman documents. The first proven historical event was the arrival of a Roman fleet under Drusus in 12 BC; the ships sailed into the course of the Ems river and returned.