The remains of Neolithic and Bronze- and Iron-Age settlements are present. These were followed by early Celtic and/or Pictish settlements. The Celtic/Pictish Christian period came to an abrupt end around A.D. 800 with the arrival of the Viking raiders and settlers. The new Viking-Norse culture continued until 1468-1469 when the Orkney and Shetland Islands were transferred to Scotland. This was done as a pledge in lieu of a dowry for the daughter of King Christian I of Denmark and Norway when she married King James III of Scotland. The pledge was never redeemed, and in 1472 Scotland formally annexed the islands. Before 1469, many Scots had moved to the islands; after 1469, their numbers continually increased. With this came a decline of the older Norse culture and language. During the late 1500s and early 1600s, the people became indentured laborers under the local Scottish lairds (lords). The inhabitants also became more isolated from Norway. They were increasingly influenced by Dutch and German fishermen and the Scottish clergy. By the nineteenth century, the people had been reduced to a serflike Status. In the mid-nineteenth century, they were freed from this and large numbers began to leave. The discovery of North Sea oil in the early 1970s has helped to stabilize life, reverse the population decline, and bring economic and social change to the islands.