Elizabeth was born at 02:40 (GMT) on 21 April 1926, during the reign of her paternal grandfather, King George V. Her father, the Duke of York (later King George VI), was the second son of the King. Her mother, the Duchess of York (later Queen Elizabeth), was the youngest daughter of Scottish aristocrat the Earl of Strathmore and Kinghorne. She was delivered by Caesarean section at her maternal grandfather's London house: 17 Bruton Street, Mayfair. She was baptised by the Anglican Archbishop of York, Cosmo Gordon Lang, in the private chapel of Buckingham Palace on 29 May,[b] and named Elizabeth after her mother, Alexandra after George V's mother, who had died six months earlier, and Mary after her paternal grandmother. Called "Lilibet" by her close family, based on what she called herself at first, she was cherished by her grandfather George V, and during his serious illness in 1929 her regular visits were credited in the popular press and by later biographers with raising his spirits and aiding his recovery.
Elizabeth's only sibling, Princess Margaret, was born in 1930. The two princesses were educated at home under the supervision of their mother and their governess, Marion Crawford. Lessons concentrated on history, language, literature and music. Crawford published a biography of Elizabeth and Margaret's childhood years entitled The Little Princesses in 1950, much to the dismay of the royal family. The book describes Elizabeth's love of horses and dogs, her orderliness, and her attitude of responsibility. Others echoed such observations: Winston Churchill described Elizabeth when she was two as "a character. She has an air of authority and reflectiveness astonishing in an infant." Her cousin Margaret Rhodes described her as "a jolly little girl, but fundamentally sensible and well-behaved".