Engelbert I (died 1 April 1096 in Saint Paul's Abbey, Lavanttal) was Margrave of Istria (1090–1096), Count of Sponheim, Kraichgau, and Pustertal and Vogt of the Archbishopric of Salzburg.
As a supporter of Pope Gregory VII during the Investiture Controversy, he lost the county of Pustertal.
[3] In the Investiture Controversy he belonged with his brothers to the party of the South Germans supporting Pope Gregory VII and, as a supporter of the Archbishop of Salzburg, Gebhard von Helfenstein, fought in the years 1085 and 1086 against the imperial appointed counter-bishop Berthold von Moosburg.
[4] In 1086 he succeeded in bringing Archbishop Gebhard back to Salzburg from exile.
[6] On 1 May 1091, Engelbert founded the Benedictine monastery of St. Paul,[7] inhabited by monks from Hirsau and their Abbot Wezilo.