Unrelated to Eastern Christianity, but one I'd highly recommend is Silent Night : The Story Of The World War 1 Christmas Truce by Stanley Weintraub (2002) It's the amazing story of how British and German soldiers on the Western Front celebrated Christmas togather in 1914. A truly moving story with accounts of soldiers from opposing armies ending up in church togather, exchanging presents, playing soccer togather and a British Lieutenant returning to his trench Christmas Eve, wondering if he had imagined the whole thing. Think I might read it again.