M.C. Escher's life under Nazi rule

[Elendil's Heir]

http://en.wikipedia.org/wiki/M.C._Escher

The great artist M.C. Escher and his family began World War II in Belgium, and then the war "forced them to move" back to the Netherlands, per Wiki. Anyone know how Escher and his family fared under Nazi rule? Was he politicized at all, active in the Underground, under surveillance, etc.? Any good bio of him out there (as opposed to books on his art, with which I'm already pretty familiar) that covers those years? I just went to an excellent exhibit on Escher at the Akron Museum of Art which had a brief timeline, but no details about his experiences during WWII.

Thanks.

[Nametag]

There's a short sketch here:

The arrival of the Nazis forced the family to move from Belgium to Holland to the village of
Baarn in 1941. The family of Escher's old teacher was taken away in the middle of the
night by the Nazis because they were Jewish. Escher found out the horrible news when he
went to take the deMesquita family some food. The Nazis left Escher alone however.
Escher and his family lived in Holland until his death.

If the GoogleDocs link doesn't work for you, you can download the PDF here.

[Elendil's Heir]

Thank you - that's more than I've been able to find elsewhere.