John Sweeney reflected on his encounters with Geert Wilders on today's From Our Own Correspondent.
He described him as "the Dark Lord of Dutch politics".
He said he was "smooth, polished, extremely articulate and very, very troubling".
He called Mr Wilders's loss of personal freedom since 2004 (due to death threats) "astonishing and grim".
And he talked of Freedom Party leader's "myopic concentration" on "one big problem" - Islam.