▁elect or ▁John ▁George ▁I ▁st ip ulated ▁in ▁his ▁will ▁that , ▁while ▁the ▁elect oral ▁dign ity ▁passes ▁to ▁his ▁el dest ▁son ▁John ▁George ▁II , ▁his ▁three ▁younger ▁brothers ▁should ▁receive ▁sec und ogen iture ▁principal ities ▁upon ▁his ▁death . ▁After ▁the ▁elect or ▁died ▁on ▁ 8 ▁October ▁ 1 6 5 6 , ▁his ▁sons ▁concluded ▁the ▁" friend - bro ther ly ▁main ▁treat y " ▁in ▁the ▁Sax on ▁residence ▁of ▁Dresden ▁on ▁ 2 2 ▁April ▁ 1 6 5 7 ▁and ▁a ▁further ▁treat y ▁in ▁ 1 6 6 3 ▁del ine ating ▁their ▁territ ories ▁and ▁so ver eign ▁rights ▁definitely . ▁These ▁treat ies ▁created ▁three ▁duch ies : ▁ ▁Sax e - Ze itz , ▁ ▁Sax e - We issen f els ▁and ▁ ▁Sax e - Mer se burg . ▁ ▁Prince ▁Maurice , ▁the ▁fourth - old est ▁son ▁received ▁the ▁districts ▁of ▁Ze itz , ▁Na um burg ▁and ▁Hay ns burg ▁in ▁the ▁former ▁Bishop ric ▁of ▁Na um burg - Ze itz ▁which ▁in ▁ 1 5 6 2 ▁had ▁been ▁sec ular ized ▁in ▁the ▁course ▁of ▁the ▁Protest ant ▁Re formation . ▁He ▁also ▁received ▁the ▁city ▁of ▁Sch le us ingen ▁in ▁ 1 6 6 0 , ▁which ▁had ▁once ▁been ▁the ▁residence ▁of ▁the ▁ext inct ▁Count s ▁of ▁Hen ne berg , ▁together ▁with ▁the ▁districts ▁of ▁Su hl ▁and ▁K üh nd orf . ▁Duke