Following on from recent BBC documentaries, this link to Bletchley Park activities during WW11 actually brings to the fore those who were the most active and most successful in decoding the German ciphers and the realisation that the first electronic computer was actually built and used at Bletchley during that time.
Here is an important link and features Professor Brian Randell:
https://www.youtube.com/watch?v=Yl6pK1Z7B5Q