B.E.Bendixen, who has written about “The Churches in Søndre Bergenhus Amt”, believed even around 1900 that there was evidence at Tyssøy of the church or the chapel of the Holy Ludvig (Louis). Two large stone blocks had lain in the western wall of the church’s nave, and this wall showed a length of 16 meters in the terrain.
A letter from the Pope Eugenius 3 in 1146 mentions St. Nikolaus church at Herdla. This church belonged under Munkeliv monastery, which was founded in Bergen by Øystein around 1110. The Herdla Church may stem from this time.
Lysekloster was the largest agricultural property in the country when it was phased out during the Reformation in 1537. In its prime this cloister encompassed two-thirds of all the farms in Os. The monks introduced and cultivated new plant species and it was probably they who stocked the waters with fish not indigenous to the area. This legacy from the Middle Ages has left a lasting mark.