1721年,法国摄政王为了维护与西班牙之间的和平,向西班牙国王提出让法国的王位继承人,11岁的路易十五,迎娶4岁的西班牙公主玛丽亚。摄政王还提议将他的女儿,12岁的德蒙邦西埃小姐,嫁给14岁的西班牙的阿斯图里王子。西班牙积极响应了这两桩婚事,并迅速组织了交换仪式。交换公主的仪式将在与两国接壤的河流中的一个小岛上盛大举行。一切就绪,就等待孩子们展现出最好的一面,但没有想到所有的计划都是徒劳的。In 1721, the Regent of France, wanting to seal the peace with Spain, offers to the Spanish King, a marriage between their respective heirs: Louis XV, age 11, and Maria Anna Victoria, the 4-year-old Spanish Infanta (princess). The Regent of France also offers to marry his daughter, Mademoiselle deè Montpensier, 12, to the Prince of Asturias, the 14-year-old heir apparent to the Spanish throne. Madrid responds enthusiastically to both proposals, and the ceremonies are promptly organized. The exchange of the princesses is to take place with great pomp on a small island, in the river bordering the two countries. Everything has been done to expect the best of the children, but nothing will proceed as planned.