Dag HammarskjöldDag Hjalmar Agne Carl Hammarskjöld ( Swedish: [dɑːg ˈhamːarɧœld] ( ) ; 29 July 1905 – 18 September 1961) was a Swedish diplomat, economist, and author. He is given credit by some historians for allowing participation of the Holy See within the United Nations that year. The Dag Hammarskjöld Crash Site Memorial is under consideration for inclusion as a UNESCO World Heritage Site. Lipsey, Roger Hammarskjold: A Life (University of Michigan Press; 2013) 670 pages; scholarly biography(University of Michigan Press; 2013) 670 pages; scholarly biography Urquhart, Brian, (1972), Hammarskjold . Velocci, Giovanni, cssr, (1998), «Hammarskjold Dag», in Luigi Borriello, ocd – Edmondo Caruana, ocarm – Maria Rosaria Del Genio – N. Suffi (dirs.