Dietrich I was the last count of Isenberg and Altena, the first count of Limburg (Limburg a.d. Lenne) (before 1215 – 1301), son of Friedrich II of Isenberg, count of Isenberg and Altena.
Dietrich I was disinherited of all his territories in the Holy Roman Empire (present-day Germany) following the execution of his father, but with the military support of his uncle the Duke of Limburg (Vesdre), recovered a small territory out of his previous possessions. He built the castles of Limburg (Hohenlimburg) and Neu Isenberg (soon lost in favour of the counts von der Mark) and took the title of count of Limburg "comes de Ysenberghe et de Limborch". [1]
- ^ Westf.UB VI nr.1089 / HVL DL01 1277.04.02