The International Labour Organisation (ILO) reached its centenary in 2019. From its beginnings in Versailles in 1919 to the present, it has developed from an organization primarily dealing with industrial labour in Europe into a global institution occupied with a broad range of aspects affecting the world of work and workers the world over. In this talk Prof. Maul will follow the development of the ILO against the backdrop of key historical conjunctures. He will place special emphasis on how the ILO adapted its core activities and the definition of international labour standards to an ever-changing international environment.