What is Richard, 6th Prince of Sayn-Wittgenstein-Berleburg?
{{Infobox royalty | name = Richard | full name = Richard Casimir Karl August Robert Konstantin | image = Prince Richard.jpg | caption = The Prince in Stockholm at [[Victoria, Crown Princess of Sweden|Crown Princess Victoria of Sweden]]'s wedding celebrations, June 2010 | succession = [[Prince of Sayn-Wittgenstein-Berleburg]] | predecessor = [[Gustav Albrecht, 5th Prince of Sayn-Wittgenstein-Berleburg|Gustav Albrecht]] | successor = [[Gustav, Hereditary Prince of Sayn-Wittgenstein-Berleburg|Prince Gustav]] | suc-type = | birth_date = {{Birth date|1934|10|29|df=yes}} | birth_place = [[Giessen]], [[Germany]] | death_date = {{death date and age|2017|3|13|1934|10|29|df=yes }} | death_place = [[Bad Berleburg|Berleburg]] | house = [[House of Sayn-Wittgenstein-Berleburg]] | spouse = {{marriage|[[Princess Benedikte of Denmark]]|3 February 1968|13 March 2017}} | issue = [[Gustav, Hereditary Prince of Sayn-Wittgenstein-Berleburg|Prince Gustav]]<br>[[Princess Alexandra of Sayn-Wittgenstein-Berleburg|Princess Alexandra]]<br>[[Princess Nathalie of Sayn-Wittgenstein-Berleburg|Princess Nathalie]] | father = [[Gustav Albrecht, 5th Prince of Sayn-Wittgenstein-Berleburg]] | mother = [[Margareta Fouché|Margareta Fouché d'Otrante]] }} '''Richard, 6th Prince of Sayn-Wittgenstein-Berleburg''' (Richard Casimir Karl August Robert Konstantin; 29 October 1934 in [[Giessen]], [[Germany]] – 13 March 2017 in [[Bad Berleburg|Berleburg]]<ref>{{cite web|last1=Paulsen|first1=Tommy M.|title=HH Prince Richard Has Died|url=http://kongehuset.dk/nyheder/hans-hoejhed-prins-richard-er-afgaaet-ved-doeden|website=kongehuset.dk|publisher=Royal Family of Denmark|access-date=14 March 2017|language=da|date=14 March 2017}}</ref>) was the head of the [[House of Sayn-Wittgenstein-Berleburg]] and husband of [[Princess Benedikte of Denmark]]. In July 2003, he underwent surgery for treatment of [[prostate]] cancer. He had undergone treatment for skin cancer.<ref>{{cite web |url=http://www.ifrance.com/Archivesgotha/revue.htm |title=iEuropa – New