He served as bishop of the Diocese of Nesqually in the Washington Territory in the United States from 1879 until his death in 1895.

Egidius Jünger was born on April 6, 1833, in Burtscheid in Rhenish Prussia (in what is today Germany).

He received his early education at the schools of Burtscheid and made his classical studies at the gymnasium of Aachen.

Under Jünger's leadership, a large cathedral was built in Vancouver, Washington, in 1888 to replace the old wooden church built in 1846 by Bishops François Norbert Blanchet and Modeste Demers, but the $50,000 financial debt the project created weighed upon him.

[4] A contemporary account described Jünger as a hard worker who lived a simple lifestyle and built good relationships with his priests and parishioners.