Anglia (German and Low Saxon: Angeln, Danish: Angel) is a small peninsula within the larger Jutland Peninsula in the region of Southern Schleswig, which constitutes the Northern part of the northernmost Germanfederal state of Schleswig-Holstein, protruding into the Bay of Kiel of the Baltic Sea. To the south, Anglia is separated from the neighbouring peninsula of Schwansen (Danish: Svans or Svansø) by the Schlei (Slien) inlet, and to the north from the Danish peninsula of Sundeved (German: Sundewitt) and the Danish island of Als (Alsen) by the Flensburg Firth (Flensburger Förde, Flensborg Fjord). The landscape is hilly, dotted with numerous lakes. Whether ancient Anglia conformed to the borders of the Anglian Peninsula is uncertain. It may have been somewhat larger; however, the ancient sources mainly concur that it also included the peninsula's territory.
Anglia has a significance far beyond its current small area and country terrain, in that it is believed to have been the original home of the Angles, Germanic immigrants to East Anglia, Central and Northern England, and the Eastern Scottish Lowlands. This migration led to their new homeland being named after them, from which the name "England" derives. Both England and the English language, thus, ultimately derive at least their names from Anglia.
The German word Angeln has been hypothesised to originate from the Germanic Proto-Indo-European root *h₂enǵʰ-, meaning "narrow" (compare German and Dutcheng = "narrow"), meaning here "the Narrow [Water]", i.e. the Schleiestuary; the root would be *angh-, "tight". Another theory is that the name meant "hook" (as in angling for fish), in reference to the shape of the peninsula; linguist Julius Pokorny derived it from the Proto-Indo-European root *ang-, "bend" (see ankle). It is also possible that the Angles may have been called such because they were a fishing people or were originally descended from such.