Also known as a Rune staff or Runic Almanac, the Runic Calendar appears to have been a medieval Swedish invention. Runic calendars were written on parchment or carved onto staves of wood, bone, or horn. The oldest one known, and the only one from the Middle Ages, is the Nyköping staff, believed to date from the 13th century. Most of the several thousand which survive are wooden calendars dating from the 16th and the 17th centuries. During the 18th century, the Runic calendars had a renaissance, and around 1800, such calendars were made in the form of tobacco boxes in brass.