OK, so we have four results in, many thanks for those:
XIII - 2
Serutan - 4 1/2
Augurey - 6
Private Hudson - 6
Suggest Augurey goes next, since PH was up before me......
Answers below:
1. What last-minute change in arrangements caused the Von Stauffenburg plot to fail?
Key was the switch from an exclosed, underground room to one with windows and doors - the bomb was sized on the basis of the much greater damage that is caused to huma bodies by an explosion in a sealed environment.
2. The death of which 'paragon of a prince' at the age of eighteen threw England into mourning and arguably led to the English Civil War?
Henry Frederick, Prince of Wales - fervently Protestant, exceptionally popular and gifted, died at the age of 18, his younger brother Charles becoming heir and going on to fall out with Parliament and lose his life on the scaffold.
3. Which European country first colonised Mauritius?
Portugal - their colony was later abandoned before the French arrived.
4. Name the Chinese admiral who commanded the 1420 imperial treasure fleet.
Zheng He
5. Whose death saved western Europe from the Mongol hordes?
Ogedei Khan, the leaders of the hordes returning to Mongolia to contend for the Khanate
6. Poland celebrates the year of its founding as 966. What did who do in this year that qualifies it to mark the founding of a nation?
King Mieszko 1 converted to Christianity and introduced written records
7. Which noble's fight with local citizens at Dover led to the exile of Earl Godwin? For a bonus, what fundamental legal difference made the quarrel unresolvable?
Eustace of Boulogne - the problem being that under French feudal customs ordinary citizens had no right or expectation of redress against any lord, whereas under English common law of the time Godwin was duty bound to protect his people and had no right of summary punishment - as Eustace demanded - even had he wanted to.
8. Which war began on 3 October 1935?
Italian invasion of Ethiopia
9. What military 'first' occured in August 1914 at Liege, Belgium?
First bombs dropped from the air (by German Zeppelin airships in support of the the asault by the German army)
10. The largest man-made explosion prior to Hiroshima occurred where, when and why?
Halifax, Nova Scotia - 6 December 1917 when a munitions ship carrying 2,500 tons of raw explosive plus a deck cargo of light oil collided with another ship entering the harbour, caught fire and exploded.
I've also awarded a markl for anyone mentioning Port Chicago, 1944 - here there was an explosion of 5,025 tons of completed munitions, roughly the same weight of explosive. The extent of damage is roughly similar althoug the loss of life was far less. It is not easy to find any source that gives a comparison of relative exposiove power, so I decided to take either.
Thanks to all who joined in - next up Augurey...