A vassal of the Kingdom of Naples associated with the State of the Presidios and a territory of the Holy Roman Empire formed from the remnants of the Republic of Pisa, it existed from 1399 to 1805, when it was merged into the Principality of Lucca and Piombino.

On 19 February 1399 Gherardo Appiani ceded Pisa and the majority of its territories, which his family had owned since 1392, to the Visconti of Milan for 200,000 florins, reserving the commune of Piombino for himself and his successors; moreover, he also took possession of Populonia, Suvereto, Scarlino, Buriano, Abbey of San Pancrazio al Fango and the islands of Pianosa, Montecristo, and Elba; forming a newly established state, the Lordship of Piombino.

[1] Gherardo had his residence built in Piombino in the small square (now Piazza Bovio) and on his death, in 1405, he left the state to his son Iacopo II.

[1] When Paola Colonna Appiano died in 1445, the Appiani heir to the lordship Emanuele, son of Gherardo, was forcibly disinherited by his brother-in-law Rinaldo Orsini.

The princes, who were also Dukes of Sora and Arce and Grandee of Spain, resided in Rome or in Isola del Liri and rarely visited the principality.

After the Treaty of Aix-la-Chapelle, the situation calmed down and the princes, given their remoteness, left the local magistrates, primarily the Council of the Elders, to administer the state in their name.

At the behest of Napoleon I, on 23 June 1805, the Principality of Lucca and Piombino was created, assigned to his sister Elisa Bonaparte and her husband Felice Pasquale Baciocchi.