Her father, Lord Rosebery, in addition to a life in Liberal politics and serving briefly as prime minister, collected Napoleonic memorabilia and wrote biographies, including one of Napoleon and another of William Pitt the Younger. Her mother, the Countess Hannah, was at one time reputed to be the richest woman in England. In her childhood Sybil was taught by governesses and divided her time between the family's Lansdowne House in London and their many country houses, which included Dalmeny House and Mentmore Towers. From the time she was a baby, Lady Sybil was often left by her parents in the care of servants, supervised by her father's sister Lady Leconfield at the Leconfields' Petworth House. This was particularly evident shortly after Sybil's birth in June 1880, when Lord Rosebery wished to visit Germany for three months to take a cure at a German spa for what is now thought to have been a nervous breakdown. He had no great feeling for proximity to small babies. His wife dutifully accompanied him, but Rosebery reported that she savoured every detail of daily letters from London concerning Sybil.