In a letter sent Friday to French bishops, Pope Francis paid homage to the men who fought in the D-Day invasion of Normandy 70 years ago, which was one of the key turning points in World War II.

"His Holiness Pope Francis unites himself wholeheartedly to the intercession of those who commemorate the tragic events which occurred here seventy years ago, and prays for peace," read the letter sent June 6 by Cardinal Pietro Parolin, Vatican Secretary of State, to Bishop Jean-Claude Boulanger of Bayeux (-Lisieux), in whose territory the Normandy landing occurred.

On June 6, 1944, more than 150,000 Allied forces landed on the beaches of Normandy to begin the liberation of Europe from Nazi occupation. As many as 13,000 soldiers died that day.

The Pope's message commended the sacrifice of those who "left their homeland to land on the beaches of Normandy, with the aim of combating Nazi barbarity, freeing occupied France," and also urged that we "not forget the German soldiers driven into this drama, like all victims of this war."

"It is fitting that today's generations express their full appreciation to those who accepted such a great sacrifice."

By the message, which was sent also to Cardinal Andre Vingt-Trois of Paris, Pope Francis took the opportunity to encourage Europe to remember and appreciate its Christian roots.

He wrote that "this commemoration reminds us that the exclusion of God from the lives of persons and societies can bring only death and suffering."

"The European nations can find in the Gospel of Christ, the prince of peace, the root of their history, and the source of inspiration for the establishment of ever more links of fraternity and solidarity."

The message concluded by entrusting the cause of peace to the Blessed Virgin Mary and to St. Teresa Benedicta of the Cross.