Yep the Albrecht brothers. Albrecht Discount = Aldi.
Not sure that there was a falling out but they split originally into Aldi North and Aldi South in Germany over a disagreement about selling cigarettes at the checkouts.
The aldi we have here in Ireland is the one that didn't want cigarettes sold at the checkouts.
Lidl just aped the Aldi model.
Lidl was founded as a discounter in 1930
ALDI was founded as a copycat operation of Lidl in 1946.
Dunnes Stores was founded on St. Patrick’s Street here in Cork in 1944. It opened on March 31st, and is now Ireland’s largest retailer