2004 - 100th anniversary of 13th Universal Peace Congress, Boston

2005 - 100th anniversary of 14th Universal Peace Congress, Lucerne
100th anniversary of the 1905 Nobel Peace Prize, awarded to Bertha von Suttner
(IPB Vice-President)

2006 - 100th anniversary of 15th Universal Peace Congress, Milan

2007 -  100th anniversary of 16th Universal Peace Congress, Munich
100th anniversary of the 1907 Nobel Peace Prize, awarded to Ernesto Moneta, Italy (IPB Council member) (shared with Louis Renault, France)

2008 -  100th anniversary of 17th Universal Peace Congress, London
100th anniversary of 1910 Nobel Peace Prize, awarded to Fredrik Bajer, Denmark (first President of IPB) (shared with Klaus Arnoldson, Sweden, founder of Swedish Peace and Arbitration Society – an IPB member organisation)

2010 -  100th anniversary of 18th Universal Peace Congress, Stockholm
100th anniversary of the 1910 Nobel Peace Prize, awarded to the International Peace Bureau itself.

2011 - 100th anniversary of 1911 Nobel Peace Prize, awarded to Alfred Fried, Austria, (IPB Council member)

2013 - 100th anniversary of 1913 Nobel Peace Prize, awarded to Henri Lafontaine, Belgium (IPB President).

Then there is a gap until after World War I....