Photos: Royals visit Poland and Germany Britain's Prince William, Duke of Cambridge, and his wife Catherine, Duchess of Cambridge, and their children Prince George and Princess Charlotte walk on the tarmac of the Airbus compound in Hamburg, northern Germany, before boarding their plane on Friday, July 21. The royal family visited Germany and Poland on a five-day European tour. Hide Caption 1 of 36

Photos: Royals visit Poland and Germany Prince George and Prince William view helicopter models H145 and H135 before departing from Hamburg on the last day of their official visit to Germany. Hide Caption 2 of 36

Photos: Royals visit Poland and Germany The royal couple tours the Airbus training facilities with Klaus Richter, chief procurement officer for Airbus, Marco Wagner, human resources director for Airbus in Germany, and Hamburg Mayor Olaf Scholz. Hide Caption 3 of 36

Photos: Royals visit Poland and Germany Catherine receives lessons on how to conduct an orchestra at Elbphilharmonie in Hamburg on Friday. Hide Caption 4 of 36

Photos: Royals visit Poland and Germany Catherine and William say goodbye to German police officers who had led their motorcade on motorcycles at Berlin Hauptbahnhof main railway station before departing for Hamburg on July 21. Hide Caption 5 of 36

Photos: Royals visit Poland and Germany William and Catherine attend a reception at Claerchens Ballhaus dance hall in Berlin on Thursday, July 20. Hide Caption 6 of 36

Photos: Royals visit Poland and Germany Prince William hammers a tap into a beer barrel as Kate, far right, watches on July 20 in Heidelberg, Germany. Hide Caption 7 of 36

Photos: Royals visit Poland and Germany William and Kate participate in a friendly rowing race on July 20, in Heidelberg. Hide Caption 8 of 36

Photos: Royals visit Poland and Germany William and Kate attempt to make pretzels on July 20, during a tour of Heidelberg's traditional German market. Hide Caption 9 of 36

Photos: Royals visit Poland and Germany The duke and duchess don lab coats during a visit on July 20, with researchers at the German Cancer Research Institute in Heidelberg. Hide Caption 10 of 36

Photos: Royals visit Poland and Germany Residents stand on a balcony decorated with a banner welcoming the Duchess of Cambridge to Heidelberg, Germany. Hide Caption 11 of 36

Photos: Royals visit Poland and Germany William and Kate toast during The Queen's Birthday Party at the British Ambassadorial Residence on July 19, in Berlin. Hide Caption 12 of 36

Photos: Royals visit Poland and Germany The royal couple speaks with General Secretary of DFB Friedrich Curtius, left, during the Queen's Birthday Garden Party. Hide Caption 13 of 36

Photos: Royals visit Poland and Germany William and Kate meet with German President Frank-Walter Steinmeier and his wife, Elke Büdenbender, at Bellevue Castle on July 19 in Berlin. Hide Caption 14 of 36

Photos: Royals visit Poland and Germany William and Kate visit the Holocaust Memorial on July 19, in Berlin. Hide Caption 15 of 36

Photos: Royals visit Poland and Germany William and Kate visit the Brandenburg Gate on July 19, in Berlin. Hide Caption 16 of 36

Photos: Royals visit Poland and Germany German Chancellor Angela Merkel shows William and Kate a view from the Federal Chancellery on July 19, in Berlin, in this In this handout photo from the German government's press office. Hide Caption 17 of 36

Photos: Royals visit Poland and Germany Kate, William and Merkel greet well-wishers shortly after the royal couple's arrival in Berlin. Hide Caption 18 of 36

Photos: Royals visit Poland and Germany The royal family arrives at the airport in Berlin on July 19, for a three-day visit to Germany. Hide Caption 19 of 36

Photos: Royals visit Poland and Germany Basil Kerski, director of the European Solidarity Centre, accompanies the royals on July 18, as they visit Gdansk, Poland. Hide Caption 20 of 36

Photos: Royals visit Poland and Germany William and Kate lay flowers at the Monument to the Fallen Shipyard Workers of 1970 at the European Solidarity Centre in Gdansk, Poland. Hide Caption 21 of 36

Photos: Royals visit Poland and Germany Prince William visits with performers from Gdansk Shakespeare Theatre, of which he is a patron, on July 18, in Gdansk, Poland. Hide Caption 22 of 36

Photos: Royals visit Poland and Germany Kate and William are shown a piece of amber by a local craftsman during a visit on July 18, to the Gdansk central market in Poland. Hide Caption 23 of 36

Photos: Royals visit Poland and Germany A crowd lines the street to greet the royal couple during their visit to Gdansk, Poland. Hide Caption 24 of 36

Photos: Royals visit Poland and Germany Former Nazi concentration camp prisoners Manfred Goldberg, second from left, and Zigi Shipper speak with the royal couple during their visit to Stutthof, a World War II Nazi concentration camp in the village of Sztutowo, Poland. Hide Caption 25 of 36

Photos: Royals visit Poland and Germany William and Kate view a display at the Stutthof Nazi concentration camp site in the village of Sztutowo, Poland. Hide Caption 26 of 36

Photos: Royals visit Poland and Germany William speaks as Kate, left, and Polish President Andrzej Duda and his wife, Agata Kornhauser-Duda, listen during a Queen's birthday party on July 17, in the Orangery in Lazienki Park in Warsaw, Poland. Hide Caption 27 of 36

Photos: Royals visit Poland and Germany William and Kate make a toast during a Queen's birthday party in Poland. Hide Caption 28 of 36

Photos: Royals visit Poland and Germany William wears virtual-reality goggles as Kate laughs during a meeting with young Polish entrepreneurs in Warsaw, Poland. Hide Caption 29 of 36

Photos: Royals visit Poland and Germany Kate speaks with a WWII veteran during a visit to the Warsaw Rising Museum on July 17, the first day of the British royal couple's official visit to Poland. Hide Caption 30 of 36

Photos: Royals visit Poland and Germany Duda, left, and William, kneel as they light candles during a visit to the Warsaw Uprising Museum while Poland's first lady, second from right, and Kate look on. Hide Caption 31 of 36

Photos: Royals visit Poland and Germany William poses for a selfie with a woman on July 17, as a crowd gathers outside the Presidential Palace in Warsaw, Poland, to greet the royals. Hide Caption 32 of 36

Photos: Royals visit Poland and Germany Children welcome Kate in front of the presidential palace in Warsaw upon the royal family's arrival in Poland. Hide Caption 33 of 36

Photos: Royals visit Poland and Germany Duda and his wife greet the Duke and Duchess of Cambridge at the Presidential Palace in Warsaw on the first day of the royal visit to Poland. Hide Caption 34 of 36

Photos: Royals visit Poland and Germany The royal couple disembarks with their children upon arrival on July 17, at the airport in Warsaw, Poland. Hide Caption 35 of 36