My paternal grandfather was born in Berlin and, like my maternal grandfather, also enlisted early on in the war. He fought for a time in France, where he was shot in the leg and then, after he had recuperated, he was sent to the Russian front which was notoriously freezing and conditions were unbearable. He was awarded the Iron Cross for his bravery. Ironic really, as he went on after the war to marry a girl with Jewish connections (he was Lutheran) and in 1939 they were forced to flee for their lives and settle here in England, some number of months after their two teenage sons (one of them my father) had already come here with the Kindertransport.
My German grandfather in exact centre front row.
When my mother and father got together in the Second World War, announced their engagement and introduced both sets of parents to one another, my two grandfathers amicably shook hands and joked "I bet you were the b*****r that shot my leg/eye". It was good that they could be so forgiving, given the extent of their injuries. It does however highlight the futility of war - human beings but for the grace of God on opposite sides ordered to kill one another. We haven't learned the lesson of the last hundred years - war still goes on all over the world at any given time and will continue to do so alarmingly, if Kim Jong-Un and Trump get too trigger-happy.