The author investigates, from the standpoint of diplomatic and international history, a question which confronted and divided the Great Powers of Europe during the years 1855-9, namely, whether the principalities of Moldovia and Wallachia should be politically united. His attention has centred on the conflicting policies of the Powers, whose action was to determine the early destinies of Rumania, and upon the reaction of the question upon their interrelations. The work is based on numerous Foreign Office MSS, and was first published in 1929.