Q: Barbara, Houston, United States of America
Can you give me details of the outfit with the straw hat worn by The Queen at this year's Ascot races.  I thought the hat especially was delightful.

The outfit you refer to was worn by The Queen on the fourth day of this year's Royal Ascot. 

The loose-fitting coat in pale sand colour was of very fine wool crepe with turn down collar - also called "edge-to-edge".  It was teamed with a two piece suit dress in ivory flower pure silk satin, with a scarf to match in same material.  Both pieces were designed by Karl Ludwig.

Her Majesty's hat was designed by Rachel Trevor-Morgan and was of woven pale sand-coloured straw with flowers of floral printed silk material.

Q: Robert, Middlesbrough
For how many years have coronations taken place at Westminster Abbey and where did they take place before the abbey was built?

The crowning of the Sovereign has taken place at Westminster Abbey for the last 900 years.  Before the Abbey was built, coronation ceremonies were carried out at Winchester, Canterbury, Kingston upon Thames, Gloucester, Oxford and Bath.    

Q: Stephen, Weston-super-Mare
Please can you tell me more information about The King's Troop Royal Horse Artillery who participated in Trooping the Colour?  Why is it not known as The Queen's Troop?

The King's Troop Royal Horse Artillery was first formed in 1793.  Before the Second World War, a succession of Horse Artillery Batteries were stationed in London. The last was mechanised in 1939 and it was King George VI's express wish that, after the war, a Troop of Royal Horse Artillery, mounted and dressed in the traditional manner, should once more be seen taking part in the great ceremonies of State. 

This unit became The Riding Troop Royal Horse Artillery and in October 1947 was renamed The King's Troop.  On The Queen's accession in 1952, Her Majesty decided that the title be retained in memory of her father. 

Today, the duties of The King's Troop - as part of the Household Troops - include the firing of Royal Salutes in Hyde Park on royal anniversaries and State occasions, such as royal birthdays and the State Opening of Parliament, and providing a gun carriage and team of black horses for State and Military funerals.
 
It also takes its part on other ceremonial occasions such as The Queen's Birthday Parade, also known as Trooping the Colour, the annual Cenotaph Remembrance Sunday parade, and the Lord Mayor's Show.

The King's Troop forms part of the Royal Regiment of Artillery, of which The Queen is Captain-General, and is under the command of the Major General commanding London District.  When on parade with its guns The King's Troop takes precedence over all other Regiments and has the honour of parading on the right of the line.
 
Q: Julia, Hove
Please can you tell me whether Queen Mary's first name was in fact Victoria?  I think so but my husband disagrees with me.

You are correct.  Queen Mary was christened Princess Victoria Mary Augusta Louise Olga Pauline Claudine Agnes.  She was known in her family as May but used the names Victoria Mary officially until she became Queen.

Q: Axel, Oslo, Norway
What is the role of the Vice-Chamberlain of the Royal Household?

The Vice-Chamberlain is one of three political appointees to the Royal Household from the House of Commons.  Although the role has little to do with the Lord Chamberlain, the holder fulfils a corresponding function as a channel of communication between the Sovereign and the House of Commons, as does the Lord Chamberlain for the House of Lords. 

The Vice-Chamberlain's principal duties are performed in the Whips' Office and are essentially to do with party politics.  However, part of his duty is to keep the Sovereign informed of the activities of the House of Commons.  To this end, he writes every day on which Parliament is sitting, before dinner, an account of Commons' proceedings up to that point, along with a note of any happenings of importance the previous day after his report was written.  This document is confidential and is read only by The Queen.

For the State Opening of Parliament, the Vice-Chamberlain remains at Buckingham Palace - an archaic requirement today, since theoretically he is there to ensure Her Majesty's safe return.