Almost everything known about Adam of Bremen comes from his own book. He arrived at the cathedral chapter of Bremen around 1066, probably from eastern Franconia in what is now southern Germany, and served there as a canon and as master of the cathedral school. Between roughly 1073 and 1076 he composed the Gesta Hammaburgensis Ecclesiae Pontificum, the Deeds of the Bishops of the Church of Hamburg, a four book Latin history of the archdiocese that held the papal commission for the mission to Scandinavia and the Baltic.
The first three books trace the archbishops from the eighth century to Adam's patron Adalbert, whose troubled reign he describes with unusual candor. The fourth book, the Descriptio insularum aquilonis, breaks from episcopal history into geography and ethnography, describing Denmark, Sweden, Norway and the islands of the north together with the customs and religion of their peoples. Adam did not travel far to gather this material. His most important informant was the Danish king Sven Estridsen, at whose court he collected traditions, and he supplemented what he heard with older written geography and mission reports. He continued to add marginal notes, the scholia, until about 1081, after which nothing more is heard of him. The work survived in the chapter library and became a foundation text for the medieval church history of the whole northern world.