Conversation so far:
What are the Nuremberg trials?
The Nuremberg trials were a series of military tribunals held after World War II by the Allied forces under international law and the laws of war.
Did William J. Donovan prosecute Nuremberg trial criminals himself?
William J. Donovan criticized William Harding Jackson's lack of skill and experience at putting together a case and at courtroom examination and cross-examination. Jackson removed Donovan from the team

Question: Who invited him?
Self-contained rewrite: Who invited William J. Donovan to the Nuremberg trials prosecution team?