Unteraargau co-extensive with modern Aargau? edit

I question the first sentence: "The Unteraargau * * * corresponds approximately to the modern canton of Aargau." Does the Unteraargau include Fricktal, Baden or Freie Ämter? I thought that the Unteraargau corresponds to the southwest quarter of the modern canton of Aargau.--Rpclod (talk) 12:44, 24 June 2009 (UTC)Reply