In the 8th century CE,  Vikings surged across the misty seas. They came from Scandinavia  in Northern Europe but would travel far and wide. Some plundered and settled  in the British Isles and France; others braved Artic exploration or forged clever new trade routes  to the Middle East. With their steely navigational skills,  advanced long-ships and fearsome tactics, the Vikings sustained their seafaring  for over three hundred years. But for all their might,  they left few monuments. Instead, fragments of stone,  bark, and bone provide the keys to their culture. Found in graves, bogs,  and sites of ancient settlements, many of these objects are inscribed with messages in Old Norse  written in runic letters. But the Vikings also scratched runes into household goods, jewellery, weapons, and even shoes. Deciphering these messages  is no easy task. Runes are short, straight,  and diagonal lines that make up an alphabet  called the “futhark.” All classes of people spoke and wrote  this language, in many different dialects. There was no standard spelling,  they wrote the individual runic letters by pronouncing the sounds  of their regional accents. Some of these inscriptions also bore  the influence of other cultures the Vikings interacted with— the runic inscription “love conquers all,” for example, is originally a Latin phrase  from the poet Virgil. Many, like the enigmatic Rok runestone,  were carved in verse, highlighting the tradition  of Old Norse poetry. So even though modern runologists  can read runes, their meaning isn’t always obvious. Still, in spite of the remaining  mysteries, many inscriptions memorializing the dead and recording local histories  have been deciphered— along with some  containing magical incantations. The Ramsund runes in Sweden are carved  on a rocky outcrop beside a bridge for travelers passing over swampy ground. This causeway was commissioned  by a prominent local woman named Sigríðr. She proclaimed both her importance  and her family’s power by carving their names in stone, and even associated herself  and her family with mythical heroism by carving illustrations of Sigurd  the dragon slayer. In the town of Jelling in Denmark, two standing stones from the 10th century memorialize different generations of a royal family. The first was erected by King Gorm the Old in memory of his Queen Thyrvi, and the second by their son,  Harald Bluetooth, after Gorm’s death. The stones announce the power  of this Viking Age dynasty, and they are among the earliest historical documents of Denmark. They indicate that Denmark  was the earliest major Viking Age kingdom, by telling that Harald controlled  southern Norway, and that he converted to Christianity. Today, Harald Bluetooth’s initials  make up the Bluetooth logo. The 10th century warrior poet Egil  was a well-known carver of runes. According to poetic accounts, he once  carved runes on a horn filled with poison, causing the horn to shatter. In another story, Egil saves a young girl’s life  by placing a piece of whale bone carved with healing runes  under her pillow. Norse poetry tells of runic spells,  cast to ensure calm seas, safe childbirth and triumphant battles. But the exact nature of these spells  isn’t fully understood— many of the inscriptions on swords, axes, and spears are indecipherable. Other objects, like the Lindholm amulet, have inscriptions that could be  incantations, riddles, or religious messages. While it’s difficult to pinpoint the end of the Viking era, by 1100 CE their sea-borne expansion  had mostly come to an end. However, people continued to speak  versions of Old Norse throughout Scandinavia; and runes remained in use in rural areas into the 19th century. Today, many runestones remain standing  at their original sites. The inscription on the Danish Glavendrup stone has fearsomely declared  for a thousand years: “A warlock be he who damages this stone or drags it in memory of another!”