| William I | |
| Landgrave of Hesse-Rotenburg | |
| House: | Hesse |
| Issue: | Maria Eleonore, Countess Palatine of Sulzbach Ernst II Leopold, Landgrave of Hesse-Rotenburg |
| Father: | Ernest, Landgrave of Hesse-Rheinfels |
| Mother: | Countess Maria Eleonore of Solms-Lich |
| Spouse: | Maria Anna of Lowenstein-Wertheim |
| Birth Place: | Kassel |
| Death Place: | Langenschwalbach |
William I (15 May 1648, Kassel20 November 1725, Langenschwalbach) was Landgrave of Hesse-Rotenburg from 1693 until his death.[1]
He was a son of Ernest I of Hesse-Rheinfels-Rotenburg (1623-1693) and his wife, Countess Maria Eleonore of Solms-Lich (1632-1689). William was nicknamed the Elder to distinguish him from his nephew, William of Hesse-Wanfried.
After his father's death in 1693, William ruled one half of the Rotenburg Quarter, the quarter of Hesse-Kassel which Landgrave Maurice of Hesse-Kassel had distributed as fiefs among the sons of his second wife, Juliane. He officially resided in Rotenburg an der Fulda, but he often stayed in Langenschwalbach in the Taunus area. His descendants ruled the Rotenburg Quarter; his grandson, Constantine reunited all the parts of the Quarter.
William's dominions included the lower part of the County of Katzenelnbogen and the districts and castles of Burg Rheinfels, Reichenberg and Hohenstein as well as shares of Umstadt and Vierherren an der Lahn. He swapped the district and city of Eschwege with his brother Charles for the district and city of Rotenburg. He also held the dominions of Falkenberg, Cornberg and Langenschwalbach and he received a share of the Hessian toll on the Rhine and custom duties on wine, agriculture and wool and the toll at Boppard.
William died in 1725 and was buried in the Catholic Church of St. Elizabeth in Langenschwalbach.
William married on 3 March 1669 in Rochefort Countess Maria Anna of Löwenstein-Wertheim-Rochefort (1652–1688), sister of Maximilian Karl, Prince of Löwenstein-Wertheim-Rochefort. Anna died in 1688 and was buried in the Franciscan monastery in Boppard. With her, he had eight children, including his successor, Ernest II Leopold.