[9] On 30 June 1183, the Emperor Frederick Barbarossa granted Bishop Pietro the county of Luni, the shoreline, and the port of Amelia (Ameglia).

[11] Bishop Walterius and the Canons of the Cathedral also negotiated a pact, which was approved by Pope Innocent III on 7 March 1202 in the bull In eminenti sedis.

[12] On 25 March 1204, Pope Innocent III confirmed the transfer of the seat of the diocese of Luni to the town of Sarzana.

[13] In 1217, Pope Honorius III removed the territory of Porto Venere from the diocese of Luni and assigned it to Genoa.

In October 1254, Bishop Guglielmo approved the transfer to Nicolò Fieschi the castles of Tivegna and Castiglione, and the woods of Padivarmo; the grants were confirmed in the same month by Pope Innocent IV.

[16] In 1306 Dante went to Sarzana, and succeeded in settling a dispute between Bishop Antonio Camulla and the Marchese Franceschino Malaspina, the most important of the diocese's vassals.

On 13 February 1355 Emperor Charles IV conferred on the bishops of Luni the title of prince of the Holy Roman Empire.

[18] Antonio M. Parentuccelli (1495), a cousin of Pope Nicholas V, built the episcopal palace and the church of S. Maria delle Grazie.

In December 1187, Pope Gregory VIII granted the petition of the Bishop and Canons of Luni to transfer the episcopal seat to Sarzana, but he died before the transaction could be completed.

[19] The Cathedral church in Sarzana was dedicated to S. Basilio, and later to the Assumption of the Body of the Blessed Virgin Mary into Heaven.

[30] The Council of Trent, in its 23rd Session, meeting on 15 July 1563, issued a decree, the 18th chapter of which required that every diocese have a seminary for the training of clergy.

[31] On 6 September 1601, the Canons of the Cathedral named a representative to the committee to prepare the plans of the seminary which had been ordered by Bishop Salvago in his diocesan synod of 1595.

When the Directory had been overthrown, and in 1802, with the permission of First Consul Napoleon Bonaparte, the Pope's remains were being returned to Rome, the funeral cortege passed through Sarzana.

On 2 February a solemn funeral Mass was sung in the Cathedral by Archbishop Giuseppe Maria Spina,[35] who had accompanied Pius throughout his ordeal.