  Weihrauch complexity is now an established and active part of mathematical
logic. It can be seen as a computability-theoretic approach to classifying the
uniform computational content of mathematical problems. This theory has become
an important interface between more proof-theoretic and more
computability-theoretic studies in the realm of reverse mathematics. Here we
present a historical account of the early developments of Weihrauch complexity
by the Hagen school of computable analysis that started more than thirty years
ago, and we indicate how this has influenced, informed, and anticipated more
recent developments of the subject.
