This is a nice gesture on the part of both countries. For the 800th anniversary of the cathedral at Reims, France, six new windows designed by a German artist (I recommend going to that BBC link and watching the video) will be installed as some of the finishing touches of the massive rebuilding and restoration of the medieval structure.
Twenty-five French kings were annointed there, one in the presence of St. Joan of Arc. But at the outset of World War I, German guns trained on the cathedral as they advanced toward Paris. According to one account, the pattern of German shelling in the surrounding town suggested that the Germans sole target in Reims was Notre Dame de Reims. And when things were going poorly elsewhere on the front, they would open up again on the defiant Lady, still standing.
The Germans battered the cathedral, destroying most of the glass, many of the hundreds of statues on the exterior, and leaving gaping holes throughout, but they could not completely destroy it.
The restoration effort began apace in 1919 and the cathedral was completely re-opened in 1938, partly with funding from the Rockefellers, and work on the interior and windows has continued since that day. Commissioning a German artist to design these six windows was a very intentional act, aimed at continuing the reconciliation and moving forward with healing old European wounds.