In Old Norse, the use of bynames was quite common. They were nicknames put before or after the given name. If a byname was well established, it was sometimes used without the given name as well.
Many Viking kings had well-known bynames e.g. Harald Bluetooth (Old Norse Haraldr Blátǫnn) or Sweyn Forkbeard (Old Norse Sveinn Tjúguskegg), but also normal people, both men and women.
Most of those bynames stand in connection with the person's:
A/Á B D E F G H I/Í J K L M N O/Ó P R S T U/Ú V Y/Ý Þ Æ Ǫ/Ø/Œ