The MIGRATION conferences provide an international forum for the timely exchange of scientific information on chemical processes controlling the migration behaviour of actinides and fission products in natural aquifer systems. Experimental investigations and predictive modelling of these processes are the main topics of the conferences. The information generated from the MIGRATION conferences is the basis for the mechanistic understanding of the migration behaviour of long-lived radionuclides in the geosphere, which is essential for the long-term performance assessment of nuclear waste disposal. The first MIGRATION conference was held in 1987 in Munich, Germany. It was followed by MIGRATION ‘89 in Monterey, California, USA; MIGRATION ‘91 in Jerez de la Frontera, Spain; MIGRATION ‘93 in Charleston, South Carolina, USA; MIGRATION ‘95 in Saint-Malo, France; MIGRATION ‘97 in Sendai, Japan; MIGRATION ‘99 at Lake Tahoe, Nevada, USA; MIGRATION ‘01 in Bregenz, Austria; MIGRATION ‘03 in Gyeongju, Korea; MIGRATION ‘05 in Avignon, France; MIGRATION ‘07 in Munich, Germany; MIGRATION ’09 in Kennewick, Washington, USA; MIGRATION '11 in Beijing, China; MIGRATION '13 in Brighton, UK; MIGRATION '15 in Santa Fe, New Mexico, USA; MIGRATION '17 in Barcelona, Spain; MIGRATION '19 in Kyoto, Japan; and Migration '23 in Nantes, France.