In LOCATION@1 , it became obsolete in the Middle Ages and was replaced with duke -LRB- hertig/hertug -RRB- ; in later medieval LOCATION@2 , it became the equivalent of the continental count -LRB- in LOCATION@3 in the earlier period , it was more akin to duke , while in LOCATION@4 it assimilated the concept of mormaer -RRB- .

In LOCATION@1 , it got out of use in the Middle Ages , whereas , in LOCATION@2 , it became synonymous with the continental count .
