How were the Allied leaders of the Second World War safely transported to places such as Tehran and Yalta?

by Certainly-Not-A-Bot

Even in the later years of the war when the Allies mostly had naval and aerial supremacy, I'm still left wondering how it wasn't deemed too big of a risk for someone like Churchill to leave the UK. How did they plan the trips to avoid Germans attacking them, either intentionally or accidentally, and did the Germans ever try to intercept the leaders as they moved around?

Bigglesworth_

I'm glad you asked! See How dangerous was it for officials travelling during WW2, and how did they do it? for the most recent version of my work-in-progress, I'm afraid I haven't had a chance to work on it further since then so still haven't quite got to Tehran, but still hoping to finish it some day...