Princess Sophie of Prussia (Sophie Dorothea Ulrike Alice; 14 June 1870 – 13 January 1932) was Queen of the Hellenes as the wife of King Constantine I. She was a younger sister of Wilhelm II, German Emperor, and a granddaughter of Queen Victoria of the United Kingdom.
On 14 June 1870, Sophie was born in the New Palace in Potsdam, Prussia, to then Crown Prince Frederick of Prussia (later German Emperor) and Victoria, Princess Royal of the United Kingdom, herself the eldest daughter of Queen Victoria and Albert, Prince Consort. She was christened the following month, though all the men present were in uniform, as France had declared war on Prussia. Sophie's mother described the event to Queen Victoria: "The Christening went off well, but was sad and serious; anxious faces and tearful eyes, and a gloom and foreshadowing of all the misery in store spread a cloud over the ceremony, which should have been one of gladness and thanksgiving".
Sophie was known as "Sossy" during her childhood (the name was thought to have been picked because it rhymed with "Mossy", the nickname of her younger sister Princess Margaret). Sophie was also a sister of William II, German Emperor, Princesses Charlotte and Victoria of Prussia, as well as Princes Henry, Waldemar and Sigismund of Prussia.
Duchess Sophie of Prussia (c. 31 March 1582 – c. 24 November 1610) was a German princess of the Duchy of Prussia and a member of the House of Hohenzollern.
Sophie was the daughter of Albert Frederick, Duke of Prussia, and Marie Eleonore of Cleves. She was courted by Wilhelm Kettler, son of Gotthard Kettler of Courland and Anna of Mecklenburg-Schwerin. Their marriage contract was signed in Königsberg on 5 January 1609. Sophie died on 24 November 1610, four weeks after the birth of her only son, Jacob, who later succeeded his paternal uncle Friedrich Kettler as Duke of Courland.