Did he even know he was Polish
Sir Joseph Rotblat? I'm sure he did.
He was from Warsaw, educated at the Free University and at the University of Warsaw there, worked in Warsaw and was over 30 when he moved to the U.K. in 1938.
Given that he worked on Britain's very important Tube Alloys Project (without which the U.K. and the U.S. wouldn't have had access to atomic bombs) the world would be a very different place. Without him and his colleagues, Stalin would have got the bomb first and that is an alternative history timeline that I would not want to read.
I'd guess that his sisters Ewa and Halina and his brother Mieczysław also knew who they were.
The Polish Ambassador to the U.K. unveiled a memorial to him in London, outside the premises of the nuclear non- proliferation organisation he co-founded.
