When I was over for the World Scout Jamboree in July/August 2007, we had three days of touring in & around London before the big event. We spent about 1/2 day or less in six locations. My troop went to Eton/Windsor the first day, the Tower and Greenwich the second day, and St. Paul's, Westminster Abbey and the British Museum the third day. As it was, we didn't have enough time to read all of the exhibit descriptions, etc. We just hit the highlights at each place. I personally could have spent a full day at any one of the locations I visited. For a Tudor historian, the Tower, Westminster Abbey and Windsor would probably be more than enough. Transportation (coaches - tour buses for the North Americans) and lodging (in Hertfordshire) was arranged for us, so we didn't have to worry about figuring out the Underground, etc. or waiting for public transportation.

For someone accustomed to July in the Ohio River Valley (high temps in the mid to upper 90's F and humidity running about the same - 80% and better) the weather in London/Essex was fantastic - and they were having a 'heat wave' (high temps in the mid to upper 80's F and humidity approaching 50%)! In fact, the guys in my troop, and those from locations further south and west of us in the U.S., needed jackets and occasionally long pants in the mornings.

Whatever your decision, enjoy the trip.