sentences:  An important challenge of his tenure as governor of the NBB was the European monetary integration, which was initiated under Jacques Delors.Alfons Verplaetse became a member of the board of governors of the European Monetary Institute in 1994 and of the Governing Council of the European Central Bank in 1998.He remained in office until 1999 to oversee the introduction of the euro to replace the Belgian franc, on 1 January 1999, as the official currency of Belgium.