Egeln is situated on the riverBode, approx. 15 kilometres (9.3 mi) northwest ofStaßfurt, and 25 km (16 mi) southwest of the state capitalMagdeburg on the road toHalberstadt. A train connection to Staßfurt viaHecklingen is provided at Egeln station.
The fertile Bode basin had been settled since thePaleolithic; the town's name may refer toAnglian tribes which in the 2nd and 3rd century AD moved from theBaltic coast southwards to present-dayThuringia. A fortification at the site namedOsteregulon is mentioned in a 941 deed of donation, issued by German kingOtto I when he enfeoffed Siegfried, firstborn son of MargraveGero, with the surrounding estates. The castle secured a causeway across the Bode river, part of an important trade route from the cities ofGoslar andQuedlinburg to theOttonian residence in Magdeburg.
After Siegfried's early death, the area passed into the possessions of newly establishedGernrode Abbey. Merchants and craftsmen settled there, and a fortified town was laid out in the 11th century at the behest of theSaxon counts from theAscanian dynasty. A parish church was first mentioned in 1206. Conquered by the Lords ofHadmersleben about 1250, the Egeln citizens were vested withtown privileges; Otto of Hadmersleben founded aCistercian nunnery (Marienstuhl monastery) at the site in 1259. After the Hadmersleben dynasty became extinct in 1416, Egeln fell to thePrince-Archbishops of Magdeburg who had the castle rebuilt as a summer residence.