The ''Pactum Lotharii'' was an agreement signed on 23 February 840, between

Republic of Venice The Republic of Venice ( vec, Repùblega de Venèsia) or Venetian Republic ( vec, Repùblega Vèneta, links=no), traditionally known as La Serenissima ( en, Most Serene Republic of Venice, italics=yes; vec, Serenìsima Repùblega de Venèsia, ...

and the

Carolingian Empire The Carolingian Empire (800–888) was a large Frankish-dominated empire in western and central Europe during the Early Middle Ages. It was ruled by the Carolingian dynasty, which had ruled as kings of the Franks since 751 and as kings of the ...

, during the respective governments of

Pietro Tradonico Pietro Tradonico ( la, Petrus Tradonicus; c. 800 - 13 September 864) was Doge of Venice from 836 to 864. He was, according to tradition, the thirteenth doge, though historically he is only the eleventh. His election broke the power of the Partici ...

and Lothair I. This document was one of the first acts to testify to the separation between the nascent Republic of Venice and the

Byzantine Empire The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinopl ...

: for the first time the Doge, on his own initiative, undertook agreements with the Western world. The treaty included a commitment on the part of the Venetians to help the empire in its campaign against the Slavic tribes. In return, it guaranteed Venice's neutrality as well as its security from the mainland. However, the treaty did not end the Slavic plunderings since by 846, the Slavs were still recorded menacing cities such as the fortress of Carolea. This underscored the way the pact was more symbolic because it merely reiterated the agreements that had been already made in the past between the two empires. It concerned the rights of land use and administration of justice. It is also a valuable document that allows to know precisely the territory of the ancient Venetian duchy. The boundaries thus coincided with the old limit of the lagoons (the most extensive of currents), and the mainland reached even the Abbey of St. Hilary and the area of the ancient

Altinum Altinum (in Altino, a ''frazione'' of Quarto d'Altino) was an ancient town of the Veneti 15 km SE of modern Treviso, close to the mainland shore of the Lagoon of Venice. It was also close to the mouths of the rivers Dese, Zero and Sile. ...

. The ''Pactum'' was renewed by kings

Charles III Charles III (Charles Philip Arthur George; born 14 November 1948) is King of the United Kingdom and the 14 other Commonwealth realms. He was the longest-serving heir apparent and Prince of Wales and, at age 73, became the oldest person t ...

(887), Berengar I (888), Guy (891), Rudolf (925), Hugh (927),

Otto I Otto I (23 November 912 – 7 May 973), traditionally known as Otto the Great (german: Otto der Große, it, Ottone il Grande), was East Frankish king from 936 and Holy Roman Emperor from 962 until his death in 973. He was the oldest son of He ...

(967) and Otto III (983).Veronica West-Harling, ''Rome, Ravenna, and Venice, 750–1000: Byzantine Heritage, Imperial Present and the Construction of City Identity'' (Oxford University Press, 2020), pp. 98 & 103.

References

Treaties of the Republic of Venice Foreign relations of the Carolingian Empire 9th-century treaties 9th-century manuscripts 840 9th century in the Republic of Venice {{hist-stub

See also

References