Jieznas and Stakliškės environs pre-history
Jieznas and Stakliškės area had been inhabited from the Late Palaeolithic. Traces of Swiderian Culture have been detected in the area of the Pelekonys Village. Mesolithic people, traces of which were detected in Pelekonys Village and on the banks of the Alšyčia River, belonged to the Nemunas (Janislawice) Culture. Traces of Neolithic life have been found mainly at the river banks of Nemunas and Verknė. Traces of local dwellers attributable to the Neolithic Nemunas Culture and those of migrants belonging to Globular Amphora and Corder Ware cultures have been detected. The end of the Bronze Age is reflected in the area of the former Baudėjai Manor, where bronze artefact treasure has been detected. Roman Age inhumation burial ground has been investigated in Medžionys Village (Stakliškės Neighbourhood). Later burial monumentsbarrow cemeteries detected in the area of the villages of Pieštuvėnai and Pramiežiai and Lielionys forest (Stakliškės Neighbourhood) and being typical of the East Lithuanian Barrow Culturehad been left by the Lithuanian tribes.
Within the area of Jieznas and Stakliškės neighbourhoods, there are 15 barrows with Pieštuvėnai and Virkininkai barrows being the oldest ones, since they might be dated as far as the 1st millennium BC and attributed to the Brushed Pottery Culture. Other barrows are typical of the 1st and the beginning of the 2nd millennia. During the whole period of the 1st millennium, the dwellers of Jieznas and Stakliškės had interacted with the more southern tribes of Yotvingians (Jotvingiai).
People of Jieznas and Stakliškės area belonged to the southern province of Lithuanian tribes being formed, and this area became the core of the Lithuanian State formed later.