De Gaulle's father encouraged historical and philosophical debate between his children at mealtimes, and through his encouragement, de Gaulle grew familiar with French history from an early age. Struck by his mother's tale of how she cried as a child when she heard of the French capitulation to the Germans at Sedan in 1870, he developed a keen interest in military strategy. He was also influenced by his uncle, also named Charles de Gaulle, who was a historian and passionate Celticist who wrote books and pamphlets advocating the union of the Welsh, Scots, Irish, and Bretons into one people. His grandfather Julien-Philippe was also a historian, and his grandmother Josephine-Marie wrote poems which impassioned his Christian faith.