Now that Prince William and Kate Middleton are married, some are wondering their last name.

Like other descendants of Queen Elizabeth II and Prince Philip, William's surname is Mountbatten-Windsor, and it will be Kate's too by marriage.

As explained by the official British royal website, the Queen's descendants carry the royal surname Windsor, as well as the name Mountbatten to reflect her husband Prince Philip's surname.

The royal website explains further that the surnames are not always used, only when they are formally needed, such as the case of marriage.

While Prince William will be recorded as a Mountbatten-Windsor in the marriage registry today, he may choose a new name at a later point, specifically if and when he becomes king. As explained here, "Since a royal proclamation is not binding on succeeding rulers, King William could decide to add a name or two."

Prince William and Kate, who will go by the name of Catherine, also gained the titles Duke and Duchess of Cambridge upon their marriage today, conferred upon them by Queen Elizabeth II.

CORRECTION: An earlier version of this post stated that the duke and duchess inherited their titles, which is not the case.

More royal unions!

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  • Katie Percy and Patrick Valentine

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  • Princess Annemarie Gualtherie van Weezel and Prince Carlos de Bourbon de Parme

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  • Princess Victoria of Sweden and Prince Daniel

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  • Mark Dyer and Amanda Kline

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  • Prince Shivraj Singh of Jodhpur and Princess Gayatri Kumari of Askot

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    Married in Tbilisi on February 8, 2009.

  • Archduchess Marie-Christine of Austria and Count Rodolphe of Limburg

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  • Prince Joachin of Denmark and Marie Cavallier

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  • Peter Phillips and Autumn Kelly

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    Prince Floris, the youngest son of Princess Margriet of the Netherlands, married Aimee on October 22, 2005.

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  • Prince Felipe de Bourbon and Letizia Ortiz

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  • Barbara Cano and Bruno Gómez-Acebo

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  • Princess Martha Louise Of Norway and Ari Behn

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  • Prince Philippe Of Belgium and Miss Mathilde D'udekem D'acoz

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  • Lady Sarah Armstrong Jones and Daniel Chatto

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  • Lord David Linley and Serena Stanhope

    David Albert Charles Armstrong-Jones, Viscount Linley, married Serena on October 8, 1993.

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  • Prince Charles and Lady Diana Spencer

    Married on July 29, 1981.

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    Married on March 11, 1966.

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