World

German Chancellor Merkel, French defense minister among dignitaries remembering WWI battle

  • An opera singer wearing a dress decorated with poppies and depicting a poppy held by helpers as she sings during a ceremony at the King Albert I Monument at the Northsea town of Nieuwpoort, Belgium, on Tuesday, Oct. 28, 2014. The ceremony commemorates the WWI 100th anniversary of the First Battle of Ypres, focusing on the themes of the refusal to surrender and the flooding of the Yser plain. (AP Photo/Geert Vanden Wijngaert)

    An opera singer wearing a dress decorated with poppies and depicting a poppy held by helpers as she sings during a ceremony at the King Albert I Monument at the Northsea town of Nieuwpoort, Belgium, on Tuesday, Oct. 28, 2014. The ceremony commemorates the WWI 100th anniversary of the First Battle of Ypres, focusing on the themes of the refusal to surrender and the flooding of the Yser plain. (AP Photo/Geert Vanden Wijngaert)  (The Associated Press)

  • An opera singer wearing a dress with poppies sings during a ceremony at the King Albert I Monument at the Northsea town of Nieuwpoort, Belgium, Tuesday, Oct. 28, 2014. The ceremony commemorates the WWI 100th anniversary of the First Battle of Ypres, focusing on the themes of the refusal to surrender and the flooding of the Yser plain. (AP Photo/Geert Vanden Wijngaert)

    An opera singer wearing a dress with poppies sings during a ceremony at the King Albert I Monument at the Northsea town of Nieuwpoort, Belgium, Tuesday, Oct. 28, 2014. The ceremony commemorates the WWI 100th anniversary of the First Battle of Ypres, focusing on the themes of the refusal to surrender and the flooding of the Yser plain. (AP Photo/Geert Vanden Wijngaert)  (The Associated Press)

  • Germany's Chancellor Angela Merkel, second from left, Belgium's Prime Minister Charles Michel, left, Belgium's King Philippe, right, Queen Mathilde, second from right, and Luxembourg's Grand Duke Henri attend a ceremony at the King Albert I Monument at the Northsea town of Nieuwpoort, Belgium on Tuesday, Oct. 28, 2014. The ceremony commemorates the WWI 100th anniversary of the First Battle of Ypres, focusing on the themes of the refusal to surrender and the flooding of the Yser plain. (AP Photo/Geert Vanden Wijngaert)

    Germany's Chancellor Angela Merkel, second from left, Belgium's Prime Minister Charles Michel, left, Belgium's King Philippe, right, Queen Mathilde, second from right, and Luxembourg's Grand Duke Henri attend a ceremony at the King Albert I Monument at the Northsea town of Nieuwpoort, Belgium on Tuesday, Oct. 28, 2014. The ceremony commemorates the WWI 100th anniversary of the First Battle of Ypres, focusing on the themes of the refusal to surrender and the flooding of the Yser plain. (AP Photo/Geert Vanden Wijngaert)  (The Associated Press)

Leaders and dignitaries from former World War I enemies are uniting to mark the centenary of the first big battle on the infamous Flanders Fields which helped set the stage for four years of bloodletting by hundreds of thousands on the Western Front.

German Chancellor Angela Merkel spoke Tuesday of the "immeasurable sacrifice" the war caused and said all sides "cannot but be grateful for how much has changed since."

World War I claimed an estimated 14 million lives, including 5 million civilians and 9 million soldiers. At least 7 million troops were left permanently disabled.

The combatants dug in along a line of fortified trenches that extended from the North Sea to Switzerland — a front line that remained essentially unchanged throughout the war.