Heinrich XI was born at Greiz, Reuss, youngest child of Count Heinrich II Reuss-Obergreiz, and his wife, Countess Sophie Charlotte von Bothmer,. Heinrich succeeded his brother Henry IX as Count of Reuss-Obergreiz in 1723. After the death of Count Henry III Reuss-Untergreiz, in 1768, including the city of Untergreiz passed to the domains of the Heinrich XI and he was able to gather these possessions and guaranteed the line of succession.
Heinrich XI married on 4 April 1743 in Köstritz to Countess Conradine Reuss-Köstritz, youngest daughter of Heinrich XXIV, Count Reuss-Köstritz, and his wife, Baroness Marie Eleonore Emma von Promnitz-Dittersbach. They had eleven children:
Count Heinrich XII Reuss-Greiz
Countess Amalie Reuss-Greiz
Heinrich XIII, Prince Reuss-Greiz, married in 1786 to Princess Wilhelmine of Nassau-Weilburg, had issue.
Princess Friederike Reuss of Greiz, married firstly in 1767 to Friedrich Ludwig, Count of Castell-Rüdenhausen, no issue, divorced in 1769; Married secondly in 1770 to Friedrich Wilhelm, Prince of Hohenlohe-Kirchberg, no issue.
Prince Heinrich XIV Reuss-Greiz, married in 1797 to Marie Anne Meyer, no issue.
Prince Heinrich XV Reuss-Greiz
Princess Isabelle Auguste Reuss-Greiz, married in 1771 to Burgrave Wilhelm Georg of Kirchberg-Hachenburg, had issue.
Countess Marie Reuss-Greiz
Princess Viktoria Reuss-Greiz, married in 1783 to Wolfgang Ernst II, Prince of Isenburg and Büdingen in Birstein, no issue.
Count Heinrich XVI Reuss-Greiz
Prince Heinrich XVII Reuss of Greiz, married in 1805 to Babette von Wenz, no issue.
Heinrich married secondly on 25 October 1770 in Frankfurt am Main to Countess Alexandrine of Leiningen-Dagsburg-Heidesheim, second daughter of Christian Karl Reinhard, Count of Leiningen-Dagsburg-Heidesheim, and his wife, Countess Catharine Polyxene of Solms-Rödelheim und Assenheim; they had no issue.
Titles and styles
18 March 1722 – 17 March 1723: His Illustrious Highness Count Heinrich XI Reuss-Obergreiz
17 March 1723 – 17 March 1768: His Illustrious HighnessThe Count Reuss-Obergreiz
17 March 1768 – 12 May 1778: His Illustrious Highness The Count Reus-Greiz
12 May 1778 – 28 June 1800: His Serene Highness The Prince Reuss-Greiz
