Íslendingabók means “Book of Icelanders”. It is the title of a book, but in this post, we mean an online database created by the biotechnology company deCODE in Iceland. The aim of this Reykjavik-based company is to use population genetics studies to identify variations in the human genome associated with common diseases. So the purpose was medical. A large number of Icelanders participated in their research.
In 2003 the database the company had created was made available online but with limitations on who can see what. It very quickly became a very important genealogical database for Icelanders. To get access you must get a password, which you can only get if you have an Icelandic social security number. Users can see information on themselves, as well as all their ancestors, plus all descendants of their grandparents and great-grandparents. They can also see how they are related to anyone born after 1700 in Iceland.
The following information is available in the database:
In February 2020 the database held data on 904,000 people. The current population of Iceland is only around 400,000 and it is estimated that only about 1.8 million people ever lived on the island, since its settlement in the 9th Century. It holds information on 95% of all people born in Iceland since 1700!
The wide scope of people that users can see information on, meant that sometimes people found family members they did not know existed. Sometimes, that was a family secret or something that people had tried to hide. So not everyone was delighted with this resource!
Apart from family history research, the database also helps people check potential partners: Iceland has a very small population on a relatively remote island (at least it was before airplanes became widely used). And that means that many Icelanders are (closely) related to each other.