[285] The chronology and order of counts and kings earlier than 950 is extremely uncertain. For Barcelona, see the Gesta Comitum Barcinonensium (Redacció Primitiva), ed. L. Barrau Dihigo i J. Massó Torrents (Barcelona, 1925). The Historia de los Victoriosísissimos antiguos Condes de Barcelona, by Francisco Diago (Barcelona, 1603), is based upon original documents, but must be used with caution: