Passage: Karl and Theo Albrecht were born and raised in a Catholic family in modest circumstances in Essen, Germany. Their father, Karl Sr, was employed as a miner and later as a baker's assistant. Their mother Anna, née Siepmann, had a small grocery store in the workers' quarter of Schonnebeck, a suburb of Essen. Theo completed an apprenticeship in his mother's store, while Karl worked in a delicatessen shop. Karl served in the Wehrmacht during World War II and was wounded on the Eastern Front. After the war, the brothers jointly took over their mother's business and founded Albrecht KG. They separated that company in 1961 into Aldi Nord, covering the part of Germany north of the Ruhr under Theo Albrecht, and Aldi Süd under Karl. The first Aldi (short for Albrecht Discount) was opened in 1962.

Question: Where did Karl serve?
Wehrmacht