Task: Question Answering
Input (English): Passage: A young doctor, Robert Merivel, enters the service of King Charles II of England after having saved the King's favorite spaniel. Merivel finds himself enjoying a life of debauched pleasure and popularity at court, until the King informs him that he has arranged for Merivel to wed Celia, the King's favorite mistress. The purpose of the arranged marriage is to fool another of the King's mistresses. Merivel is given an estate named Bidnold in Suffolk, and Celia is installed in a house in Kew where the king can visit her secretly. Merivel lives a life of debauchery there, but also finds pleasure in restoring the house to its former beauty with the support of Will Gates, the man who runs the estate. However, things become complicated when Merivel breaks the King's cardinal rule by falling in love with Celia. Elias Finn, a painter commissioned by the King to paint a portrait of Celia, tricks Merivel into revealing his romantic feelings for Celia, who does not return Merivel's affections. After finding out about Merivel's romantic feelings toward Celia, the King banishes him from court back to his life as a physician.
Merivel rejoins his old friend, John Pearce, who has opened a Quaker sanitarium. There, Merivel meets Katherine, a troubled young woman whose husband walked out on her after their daughter drowned in the river. Merivel and Katherine become lovers. Pearce falls fatally ill with consumption, and while Merivel is tending to his dying friend, they discover that Katherine is pregnant with Merivel's child. After the death of Pearce, Merivel and Katherine leave.
The pair returns to London just as the Great Plague has hit. Katherine gives birth to a daughter, Margaret, via Caesarean section, but dies in the process as there is no way to ward off infection once the body has been cut open. In her dying moments, Merivel promises Katherine that he will care for Margaret, and that he loves Katherine. 
Question: What is the full name of the person the grieving mother falls in love with?
Output (English): Robert Merivel.