In addition to utilizing intact Islamic coins, the Vikings in Sweden also utilized fragmented Islamic coins for their silver content. They employed Muslim weighing scales to measure pieces and fragments, as well as complete Islamic silver coins. Archaeological evidence indicates that during the Viking Age in Sweden, the Swedes utilized weighing scales of Muslim origin and adopted the system of weights and measures from the Islamic world. This highlights the significant influence of the Islamic world on Viking Age Sweden and Scandinavia.

The Vikings learned how to acquire and utilize lenses for telescopes from the Islamic world, where Muslim advancements in optics had led to the use of telescopes centuries before Galileo’s time. Galileo’s astronomical work was greatly influenced by earlier astronomers like the 16th-century Danish astronomer Tycho Brahe, who had established astronomical knowledge in the Islamic world. Refer to the apparel and textiles section of this book. The advanced knowledge and achievements of Muslims in optics and astronomy during the ‘Abbasid era were well-documented and likely amazed the Vikings.

This included the development of the telescope, which Muslims had been using for decades before Galileo imitated their designs. Telescopes with bent lenses at each end of a tube made of hard or leather material coiled together, as employed by medieval Muslim troops, would have been very useful for the Vikings. The lens and tube, possibly obtained from the Islamic world, were used by some Vikings as compact telescopes, proving useful in various situations on land and at sea. It is likely that Vikings learned how to produce these items from the Islamic world and may have replicated them.

Historical records from English and French sources rarely mention Viking use of telescopes, likely due to bias against the Vikings by medieval writers who saw them as uncivilized raiders rather than skilled navigators, sailors, farmers, and traders. The telescope, which originated outside of Europe and predates the Scientific Revolution of the late 16th and 17th centuries, was not a topic of interest for European writers discussing Viking technology.

Islamic coins, beads, and other artifacts have been discovered in southern Sweden, particularly in regions where Vikings resided during the 9th and 10th centuries, such as Birka and Gotland. These findings indicate that Islamic coins were imported and circulated throughout Viking Age Sweden, not just on the Island of Gotland where a significant number of Islamic coins have been found.

The discovery of Islamic coins in Uppland, such as those from Baghdad, Taskhent, and Cairo, indicates that coins from different regions of the Islamic world reached Viking Age Sweden, likely through ‘Abbasid Baghdad, Sāmarrā, and Samanid Central Asia. This finding highlights the widespread presence and circulation of Islamic coins throughout Sweden, with a significant concentration in Gotland. A similar point could be made of the recent find of Islamic coins near Stockholm’s Arlanda airport on the Swedish mainland.

Additional discoveries of Islamic coins may occur in Sweden. Archaeologists in Sweden estimate that the 100,000 Islamic coins discovered represent only a fraction of the money used during the Viking Age in Sweden and a small portion of the total Islamic coins still buried in the country. Discoveries of Islamic coins in Sweden have been documented in the 21st century, as referenced in this publication. The Islamic coins found at a Viking site in Sweden vary in size and date.

Some of these coins were produced in the Islamic world over a century before they were deposited at the site. These coins arrived in Sweden decades earlier and were used and exchanged among different owners, passing from generation to generation. Evidence suggests that Swedish Vikings in Gotland continued to use Muslim currency until the mid-11th century. Professor Carlsson, the director of excavations in Gotland, Sweden, informed the writer of this article about a discovery made in 2007 at a Viking site in Klints, Gotland.

The find consisted of a silver hoard that contained Muslim coins. The wooden posts discovered at the site from the Viking Age may be dated to the mid-11th century, marking the end of the Viking Age. Therefore, Muslim coins were highly valued and utilized during this period at Gotland, an island off the coast of the Swedish mainland in the Baltic Sea.

After Sweden embraced Christianity and transitioned out of the Viking Age in the 11th century, Islamic coins might have been melted down and incorporated into the production of silver coins for the emerging Swedish state. This new state aimed to establish its own coinage and distance itself from its Viking heritage. Coinage from post-Viking Age Scandinavia was created in Denmark, Norway, and Sweden.

During the post-Viking era, all Scandinavian kingdoms aimed to mint their own coins, possibly using Muslim silver coins in the process. Many Muslim coins were melted down in post-Viking Scandinavia. However, based on recent discoveries of new coins in Sweden and other parts of Scandinavia, it is highly probable that tens or even hundreds of thousands of Muslim coins are still buried underground, waiting to be found. More attention is required in scholarly research on the introduction of different aspects of Islamic civilization, such as ceramics, textiles, glass, lamellar armor, silk, spices, and Islamic coins, into Viking Age Sweden.