ECML PKDD has developed from two independent conference series, the European Conference on Machine Learning (ECML) and the European Symposium on Principles of Knowledge Discovery and Data Mining (PKDD).
It all started in 1986 with the European Working Session on Learning (EWSL), which became the European Conference on Machine Learning as of 1993. PKDD was initiated in 1997, and both conferences have been successfully jointly organized since 2001. Over the years, they have moved closer and closer together. At the 8-th ECML PKDD (2008 in Antwerp) they were finally officially merged into a single conference.