Andrzej Hulanicki was one of the best known and most accomplished contemporary Polish mathematicians. He was the founder of the harmonic analysis research group in Wroclaw and a mentor to several generations of mathematicians. His research career spans more than 50 years; I last met him at a conference 2 years ago, and he still showed no signs of slowing down.
He died on March 23, 2008. Here’s the link to the obituary (in Polish).