<Li> Great Retreat <Ul> <Li> 1st Marne </Li> </Ul> </Li> <Ul> <Li> 1st Marne </Li> </Ul> <Li> Race to the Sea <Ul> <Li> Yser </Li> <Li> 1st Ypres </Li> <Li> Winter operations </Li> </Ul> </Li> <Ul> <Li> Yser </Li> <Li> 1st Ypres </Li> <Li> Winter operations </Li> </Ul>

Who was allied with germany during world war i apex