Albert Bourlon managed the longest sucessful solo breakaway in the history of Tour de France in 1947. It happened on the 253 km long 14th stage between Carcassone and Luchon on 11th July 1947. Burlon rode alone during the entire stage. It was his only Tour de France stage win.
There are other six over 200 km long breakaways in the history of Tour de France.