In ancient times theDanube river was a border between theRoman Empire and theGermanic tribes north of the river. The Roman camp ofPhoebiana (now Faimingen) was a bridgehead crossing the Danube. There was anApollo temple being one of the largest buildings north of theAlps in that time.
In medieval times the county of Dillingen was established. The counts of Dillingen ruled from the 10th to the 13th century, then (1258) the territory was turned over to thePrince-Bishops of Augsburg, who gained several villages for their clerical state, hence subdividing the region into several patches, which were dissolved in the early 19th century. In 1804 Dillingen and its area became part of the state of Bavaria.[2]
The district was established in 1972 by merging the former district of Dillingen (which had existed since 1804) with the western half of the former district of Wertingen. The city of Dillingen lost its status as a district-free city and became the capital of the newly established district.
The district is crossed by the river Danube, which enters the district in the southwest and leaves to the east. All cities in the district except for Wertingen are located along the Danube.
The white lion was part of the arms of the medieval county of Dillingen. The black lion in the middle is taken from the arms of the dissolved district of Wertingen. Thefleur-de-lis is from the arms of the city of Dillingen.