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In page Imperator totius Hispaniae:

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There exists a letter purportedly written by Alfonso III to the clergy of the Cathedral of Tours in 906, wherein the king is arranging to purchase an "imperial crown made of gold and precious stones, fitting to his dignity" (corona imperialis) kept at Tours.[4] Alfonso almost invariably calls himself simply "King Alfonso" (Adefonsus rex) in his surviving charters, but in the letter he uses the elaborate and high-ranking style "Alfonso by the power and assent of Christ king of Spain" (Adefonsus pro Christi nutu at que potentia Hispaniae rex). A similarly grandiose title is given to Alfonso in the contemporary Chronica Prophetica (883): "glorious Alfonso in all the Spains to reign" (gloriosus Adefonsus in omni Spanie regnaturus).[5] The authenticity of the letter is still debated.[6]