On 17 November 2008, professor Nicolaas Posthumus (1880-1960), the founder and first director of the IISH, posthumously received Israel's highest honour, the Yad Vashem medal, for helping Jews during the German occupation. The same honour was awarded his wife, Willemijn Posthumus-van der Goot (1897-1989), co-founder of the Internationaal Archief voor de Vrouwenbeweging (IAV, International Archive of the Women's Movement) and her sister An Diaz van der Goot.
The Posthumus-van der Goot family helped find shelter for Jewish children who had to go into hiding, and they cared for Bep Koster, a Jewish girl, in their own home in Leiden. The Yad Vashem ceremony took place in the Netherlands Institute for War Documentation (NIOD, Amsterdam), an institute that, like the IISH, owes a large debt to professor Posthumus.
More about N.W. Posthumus (in Dutch)
More about W.J.H. Posthumus-van der Goot (in Dutch)