10000 BC – Oldest traces of humans in Western Norway
8500 BC – Traces of leather boats in Norway
5000 BC – Traces of dugout log boats
2400 BC – Traces of plank boats
400 BC. – Boats are sawn with osiers or roots
Year 0 – Oarlocks are used on the boats, and the transition is made from paddling to rowing
300 – The Halsnøy boat
700 – The seal becomes commonplace in the Nordic region
900 – Gokstad ferry
1500-1850 – Export of Oselvar boats to Shetland
1664 – 31 active boat builders were registered around the Bjørnefjord
1750 – The Tøsdal men started building boats on the Oselvo river, giving the boat its name
1847 – First place in rowing competition with an Oselvar on Lungegårds lake in Bergen
1898 – “Os Baatbyggerforening” (Os boat builder association) is founded
1978 – First Norwegian championship in donkey sailing
1990 – Oselvarlaget is founded
1997 – Oselvarverkstaden is founded
Source: Kjell Magnus Økland: “Oselvaren, den levande båten”, Einar Østmo, Professor, Museum of Cultural History, University of Oslo
Here you can read more about the Nordic clinker boat tradition