The subtitle is British Nannies and Governesses at the World's Royal Courts.
Here's the synopsis on amazon.uk
In the nineteenth and twentieth century the wealthiest and most fashionable families across the world wanted British women to run their nurseries and educate their children. Nowhere was this more true than in the royal Courts. From Scandinavia to the Balkans, the future rulers of Europe grew up speaking English as their first language, following similar nursery routines and wearing similar clothes. Most remembered their nurses with affection - quite a few owed them their lives. Governesses did not have quite so favourable a reputation, though their role in shaping the future was, if anything, more influential. For the children, these women dominated their earliest memories and often provided their first experiences of affection: at the highest levels of society, mothers were usually distant figures. For the women, these appointments offered an opportunity to travel widely, meet a variety of people unimaginable in their home environments, and gain a privileged glimpse into the life of royalty. Mostly single, the royal governesses and nannies traded their own hopes of marriage and children for a chance to see the world. Some were so valued by the families who employed them that they never returned, being provided with comfortable homes after their employment ended.
