On 11 September 2008, the European Court of Justice (ECJ) gave its judgment in Joined Cases C-428/06 to C-434/06,dealing with the legislative autonomy in tax matters of Álava, Biscay and Gipuzkoa, the three”Historical Territories” which make up the Basque Autonomous Community in Spain.The author considers the background to the case, the decision itself and its implications. He believes that the criteria set out by the ECJ confirm the compatibility of Basque financial and tax autonomy with EC law.