Disertacija se bavi različitim aspektima materijalne kulture (naselja, pokretni nalazi, pogrebni ritual) pretpovijesnih zajednica koje su u razdoblju od kasnog brončanog doba do završetka mlađeg željeznog doba i uključivanja u okvire rimske države naseljavale prostor Donjeg Pokuplja. S obzirom na razinu istraženosti i dostupnosti građe, istraživački fokus je bio na naselju smještenom na području grada Siska, poznatom iz antičkih pisanih izvora pod imenom Segest(ik)a. Specifičan položaj Pokuplja, smještenog na razmeđu triju geografskih i kulturnih regija - istočnih Alpa, južne Panonije i zapadnog Balkana, učinio ga je značajnim dijelom u komunikacijskoj mreži željeznog doba, što se prepoznaje i u arheološkoj ostavštini. Vremenski period unutar kojeg će biti razmatran povijesni razvoj ovih zajednica može se podijeliti u dvije kronološke faze: starije i mlađe željezno doba s halštatskom i latenskom materijalnom kulturom kao dominantnim kulturnim fenomenima koji su obilježili srednjoeuropski prostor u razdoblju od 8. do 1. stoljeća pr. Kr., a koji u Donjem Pokuplju prolaze kroz lokalnu interpretaciju. Ovaj rad je analizom materijala i kontekstualnih podataka prikupljenih u recentnim istraživanjima na prostoru Siska, kao i starijih nalaza iz fundusa Arheološkog muzeja u Zagrebu i Gradskog muzeja Sisak, definirao glavne aspekte materijalne kulture „segestanske“ zajednice, a koliko su dozvoljavali dostupni podatci i ostalih zajednica s prostora Donjeg Pokuplja, čime je utvrđena dinamika naseljavanja ovoga prostora u željeznom dobu, kao i odnos prema susjednim (Dolenjska, zapadni Balkan, južna Panonija), ali i udaljenijim područjima (Italija). Definiran je i istraživački narativ kojim je konstruiran koncept Kolapijana kao protopovijesne etničke skupine, ali i kasnobrončanodobne i željeznodobne arheološke kulturne grupe.This dissertation includes an analysis and an interpretation of material culture from the prehistoric and proto-historic communities that inhabited the territory of the Lower Kupa River valley during the Iron Age. The Lower Kupa River valley region is defined as the area of the lower flow of the Kupa River from Ozalj, where it exits the mountainous region of Gorski Kotar and flows into the lowland area in the southwestern part of the Pannonian basin, all the way to where it flows into the Sava River near Sisak. This area is bordered by the Žumberak Mountains in the northwest, the Vukomeričke gorice range in the northeast, and the Slunj karst plate in the southwest. This dissertation also includes the territories of the Zrinska and Petrova gora Mountains, situated south of the Kupa River, that are seen as a contact zone with the western Balkans. As can be seen from the archaeological record, the specific position of this territory, situated at the crossroads of three geographical and cultural regions – the southeastern Alps, southern Pannonia and the western Balkans, turned it into a significant component in the Iron Age communication network. The period when these communities developed can be divided into two chronological phases: the Early and the Late Iron Age with the Hallstatt and the La Tène cultures as the dominant cultural phenomena that marked the area of central Europe between the 8th and the 1st century BC. In Donje Pokuplje, along with having a strong local character seen in the material culture, the said cultural occurances went through a specific regional interpretation the likes of which are common for the peripheral areas of larger cultural units. Considering the amount of available archaeological material and contextualized and spatial data, the focus of the analysis is on the settlement situated on the territory of today's city of Sisak, known from ancient written sources as Segesta / Segestica. The analysis also includes available data on all Iron Age sites in the Lower Kupa valley. The results of the conducted analysis can be defined through several main determinants, such as settlements, movable finds (pottery, functional and decorative elements of the attire, weapons, metal vessels) and, finally, the collective identity of Iron Age communities from the Lower Kupa valley - the Colapiani