Eleven days after Orsini's assassination attempt in France, Victoria's eldest daughter married <answer>Prince Frederick William of Prussia</answer> in London. They had been betrothed since September 1855, when Princess Victoria was 14 years old; the marriage was delayed by the Queen and Prince Albert until the bride was 17. The Queen and Albert hoped that their daughter and son-in-law would be a liberalising influence in the enlarging Prussian state. Victoria felt "sick at heart" to see her daughter leave England for Germany; "It really makes me shudder", she wrote to Princess Victoria in one of her frequent letters, "when I look round to all your sweet, happy, unconscious sisters, and think I must give them up too – one by one." Almost exactly a year later, Princess Victoria gave birth to the Queen's first grandchild, Wilhelm, who would become the last German Kaiser.
Who did Victorias eldest daughter marry?
Prince Frederick William of Prussia