 Also, the Christianisation of the South-western part of Finland is known to have already started in 10th century, and in the 12th century, the area was probably almost entirely Christian.The Swedish bishop normally involved in the eastern campaigns was the Bishop of Linköping, not the Bishop of Uppsala.The mid-12th century was a very violent time in the northern Baltic sea, with Finnish tribes such as Tavastians and Karelians as well as Swedes in frequent conflicts with Novgorod and with each other.