The Diocese of Bosa was a Roman Catholic diocese in Sardinia that was founded in 1612 and merged into the diocese of Alghero-Bosa in 1986.[1][2]
It is asserted by some that the see was originally at Calmedia, but was transferred to Bosa after the destruction of the former town; also, that the first bishop was Emilius, sent thither by Peter and martyred in 70 AD but there is no historical evidence.
Pope Gregory the Great, in one of his letters, speaks of a Bishop of Bosa, without mentioning the bishop's name.[3] In 1073 Costantino de Castro, Bishop of Bosa, who according to an inscription had built Bosa Cathedral, dedicated to Saint Peter, was appointed Metropolitan of Torres by Gregory VII. Among the most illustrious bishops of this see are numbered the learned Cardinal Giovanni Casanova (1424); G. Francesco Fara (1591), author of the first (but very inaccurate) history of Sardinia; and Serafino Esquirro, a learned theologian, who had been General of the Servites (1677).