Poll: Best Historical Episode of the Revival

The Doctor has taken multiple trips to the past and had adventures with several historical figures in each of the revival series’ so far. In this week’s poll Doctor Who TV wants to know which story deserves to go down in history as the best?

You can only pick one, so choose carefully.

Note: Single-parters only. Must be set in the past and prominently feature a historical figure (no cameos allowed, like in Let’s Kill Hitler).