Original: She was born by Caesarean section at 17 Bruton Street, Mayfair, London,Brandreth, p.103 and Roberts, p.74 and on 29 May 1926, was baptised in the private chapel of Buckingham Palace by the Archbishop of York, Cosmo Lang.
Simplified: Elizabeth was born at 17 Bruton Street, in Mayfair, London, on 21 April 1926.