The Preface of the  Annual Review of United Nations Affairs (ARUNA) 2016/2017 discusses the turbulent political context in which this UN year was situated and the challenges this creates for the new Secretary-General, António Guterres. It also comments on the principal developments during that period in the UN's major organs:  the General Assembly, the Security Council, ECOSOC, the International Court of Justice, and the UN Secretariat. These developments are discussed in detail in the commentaries in the main body of this six-volume collection of the principal documents issued by these organs during the UN year. The commentaries were prepared by Jacques Fomerand, Alexander K.A. Greenawalt, Kahlil Hamdani, John Mathiason, and Lorraine Turner Ruffing.