In this special publication, a wide cross-section of IAHR members were invited to paint a picture of IAHR over the last 70 years. In some cases their articles are reminiscences describing moments from our history - such as from Henk Jan Overbeek, Felipe Martinez or Giampaolo Di Silvio; in other cases articles about developments in the domains of our technical sections such as ecohydraulics, fluvial hydraulics or eduacation or hydroinformatics are included; and finally it has been included some regional perspectives - such as from Latin America and Korea.