Argengau was a territory of Alemannia within East Francia in the 8th and 9th centuries, being a county in the 9th century, and of the Duchy of Swabia in the 10th. It was situated north of Lake Constance, comprising Lindau. It was named for the Argen river.
- Smith, Julia M.H. "Einhard: The Sinner and the Saints" Transactions of the Royal Historical Society, Vol. 13 (2003) 55-77 cites Count Conrad of Argenau, 59.