The Epistola Adefonsi Hispaniae regis anno 906 (“letter of Alfonso, king of Spain in the year 906”) is a letter purportedly written by Alfonso III of Asturias to the clergy of the cathedral of Saint Martin's at Tours in 906. The letter is primarily about the king of Asturias purchasing a crown kept in the treasury of the church of Tours, but it also includes instructions for visiting the shrine of James, son of Zebedee, which lay in Alfonso's kingdom. An exchange of literature was also arranged in the letter. Alfonso requested a written account of the posthumous miracles worked by Saint Martin. In return the church of Tours would receive the Vitas sanctorum patrum Emeritensium, a hagiography of some early Bishops of Mérida.