Brassaï is a household name in photography and as you may know, he was born in Hungary and later went to live and work in Paris where he met everyone who was (and still is) anyone in art. Here are some of his pictures.
Probably the most famous: Parisian couple.
Diaghilev and his world-famous ballet.
Self-portrait. Smoking opium...
Mme. Bijou. I have always wondered whether this photo was an inspiration for Titanic's Mme. Bijou...? (The lady Jack Dawson made drawings of)
He spent a lot of time with Picasso photographing his works and companions and also wrote a book about his experiences with him. Conversations with Picasso is an interesting memoir that shows what Picasso the man could be like. I remember when I was readining it I was surprised how many of the facts and famous Picasso quotes come from this work.