Kaj van Vliet studied History at the University of Utrecht and obtained a Ph.D. on a research on the oldest ecclesiastical institutions of the medieaval diocese Utrecht. From 1997 he is working in the archival sector. In 1997 he started at the municipal archives of Amsterdam and changed in 1999 to the archives of Utrecht. Since 2006 he is head of the department of archives and in 2007 was appointed provincial archivist. In may 2001 he became also acting archivist of the city. He was in charge of the project Archiefbank, until the final delivery in the spring of 2011.