 Maester Aemon ( Peter Vaughan ) summons Jon and explains to him the reason why members of the Night 's Watch do not marry : it would force them to choose between their duty to the order or loyalty to their loved ones . Aemon knows this very well because he is actually Aemon Targaryen , the Mad King Aerys Targaryen 's uncle and Daenerys ' ( Emilia Clarke ) great @-@ uncle , who dutifully and reluctantly stayed at the Wall while his family members were killed or exiled when the Targaryens were overthrown . Aemon advises Jon that he must choose either his duty to the Night 's Watch or his family , but also warns that the consequences of his choice will haunt him for the rest of his life . 
