Which Star Trek captain swapped the flight deck to tread boards of a London theatre in Waiting for Godot?

The Star Trek captain who swapped the flight deck to tread boards of a London theatre in Waiting for Godot was Patrick Stewart, who played Captain Jean-Luc Picard in Star Trek: The Next Generation. He played the character of Estragon in a 1988 production of Samuel Beckett's Waiting for Godot at the Cottesloe Theatre in London.