AD, the name "Liburnia" was used not only for the territory settled by the Liburnians, but also for previously "Iapodian" territory in official usage; the Iapodians were included with the Liburnians to the court jurisdiction county of Scardona (Skradin), one of the convent seats in the provinces of Dalmatia. By the end of 330s AD, Liburnia was administratively attached to Dalmatia. However, it was still treated and recognized as a special and different area. Medieval Liburnia After the fall of the Roman Empire and probably already from 490 AD, Liburnia within Dalmatia passed to the rule of the Ostrogoths, which lasted for six decades. The region of Savia was administratively added to the Gothic province of Dalmatia; the capital city of the both provinces was Salona (Solin), a seat of the ruler "comes Dalmatiarum et Saviae". The Goths lost the most of Dalmatia and a part of Liburnia in the south-east around Skradin in 536 AD, in war against the Byzantine emperor Justinian the Great who started it to reconquer the territories of the former Western Empire (see Gothic War), while a part of Liburnia in Ravni Kotari with Zadar surrendered to the Byzantines in 552 AD. However, northern Liburnia and the rest of Classical Liburnia remained in the Gothic hands until 555 AD; after Byzantine conquest of Savia (540 AD) and Istria (543 AD) it was organized to special administrative-territorial unit of the Gothic state, known as "Liburnia Tarsatica", military province directly subject to comes Gotharum settled in Aquilea. This "military-naval" region, protected by heavy fleet, became a barrier to the Byzantine army step to Lika and Gorski Kotar, keeping safe continental road route over Tarsatica to Aquileia and northern Italy. According to anonymous Cosmographer of Ravenna (6th or 7th century), Liburnia Tarsatica considered all coastal cities from Albona (Labin) to Elona (Aenona, Nin) of Classical Liburnia and Iapodian settlements in the inland (Lika). From 550 and 551 AD, the Slavs (Sclabenoi) started to break into Illyria and Dalmatia, as recorded by Procopius; by some thinking it was beginning of Slavic colonization there, which lasted during the next few centuries. Initial ethnic nucleus under Croatian name originated in Liburnian inland from where it soon spread to all Liburnia and from there to the other regions of former Illyricum province. In the pre-Roman ages, the Liburnians had been organized in 14 municipalities (tetradekapolis), the Croats probably used existing Illyrian municipality