Victoria of the United Kingdom, (Victoria Adelaide Mary Louisa; 21 November 1840 – 5 August 1901), was German Empress and Queen of Prussia as the wife of Frederick III, German Emperor. She was the eldest child of Queen Victoria of the United Kingdom and Prince Albert of Saxe-Coburg and Gotha and was created Princess Royal in 1841. As the eldest child of the British monarch, she was briefly heir presumptive until the birth of her younger brother, the future Edward VII. She was the mother of Wilhelm II, the last German Emperor.

Educated by her father in a politically liberal environment, Victoria was married at the age of 17 to Prince Frederick of Prussia, with whom she had eight children. Victoria shared with Frederick her liberal views and hopes that Prussia and the later German Empire should become a constitutional monarchy, based on the British model. Criticised for this attitude and for her English origins, Victoria suffered ostracism by the Hohenzollerns and the Berlin court. This isolation increased after the rise to power of Otto von Bismarck, one of her staunchest political opponents, in 1862.

Victoria was empress for only a few months, during which she had opportunity to influence the policy of the German Empire. Frederick III died in 1888 – 99 days after his accession – from laryngeal cancer and was succeeded by their son Wilhelm II, who had much more conservative views than his parents. After her husband's death, she became widely known as Empress Frederick (German: Kaiserin Friedrich). The empress dowager then settled in Kronberg im Taunus, where she built Friedrichshof, a castle, named in honour of her late husband. Increasingly isolated after the weddings of her younger daughters, she died of breast cancer in August 1901, less than seven months after the death of her mother, Queen Victoria, in January 1901.

The correspondence between Victoria and her parents has been preserved almost completely: 3,777 letters from Queen Victoria to her eldest daughter and about 4,000 letters from the empress to her mother are preserved and catalogued. These give a detailed insight into life at the Prussian court between 1858 and 1900.

Victoria was born on 21 November 1840 at Buckingham Palace, London. She was the first child of Queen Victoria and her husband, Prince Albert. When she was born, the doctor exclaimed sadly: "Oh Madame, it's a girl!" The queen replied: "Never mind, next time it will be a prince!" As a daughter of the sovereign, Victoria was born a British princess. In addition, she was heir presumptive to the throne of the United Kingdom from her birth until the birth of her younger brother Prince Albert Edward (later King Edward VII) on 9 November 1841. On 19 January 1841, she was made Princess Royal, a title sometimes conferred on the eldest daughter of the sovereign. To her family, she was known simply as Vicky.

She was baptised in the Throne Room of Buckingham Palace on 10 February 1841 (on her parents' first wedding anniversary) by the Archbishop of Canterbury, William Howley. The Lily font was commissioned especially for the occasion of her christening.

The royal couple decided to give their children as complete an education as possible. Queen Victoria, who had succeeded her uncle King William IV at the age of 18, believed that she herself had not been sufficiently prepared for government affairs. For his part Prince Albert, born in the small Duchy of Saxe-Coburg-Gotha, had received a more careful education thanks to his uncle King Leopold I of Belgium.

Shortly after the birth of Victoria, Prince Albert wrote a memoir detailing the tasks and duties of all those involved with the royal children. Another 48-page document, written a year-and-a-half later by the Baron Stockmar, an intimate of the royal couple, details the educational principles to be used with the little princess. The royal couple, however, had only a very vague idea of the proper educational development of a child. Queen Victoria, for example, believed that the fact that her baby sucked on bracelets was a sign of deficient education. According to Hannah Pakula, biographer of the future German empress, the first two governesses of the princess were therefore particularly well chosen. Experienced in dealing with children, Lady Lyttelton directed the nursery through which passed all royal children after Victoria's second year and diplomatically managed to soften the unrealistic demands of the royal couple. Sarah Anne Hildyard, the children's second governess, was a competent teacher who quickly developed a close relationship with her pupils.