Complex sentence: Originally established in 1911, the GQG was only re-established on the outbreak of war in 1939; its previous incarnation had functioned from 1914 to 1919 during the First World War.
Split into simpler sentences: Originally established in 1911, the GQG was only re-established on the outbreak of war in 1939. Its previous incarnation had functioned from 1914 to 1919 during the First World War.