Not only raiders
Raiding gets most of the attention, but many Scandinavians who left home in the 9th to 11th centuries were looking for land, trade or both. Some voyages pushed into places no one had settled, and others followed rivers into the interior of eastern Europe. These movements are the reason Norse speech, names and customs show up from the North Atlantic to the edge of the Byzantine world.
Westward: the North Atlantic
Iceland. Norse settlers began arriving in Iceland in the later 9th century, traditionally around the 870s. Earlier Irish monks may have visited, but permanent settlement came from Norway and from Norse communities in the British Isles. Settlers took up farmland, brought livestock, and gradually created a society without a king, organized around local chiefs and an annual assembly, the Icelandic Althing, traditionally founded around 930. Later Icelanders wrote down their own settlement history, which is useful but written long after the fact.
Greenland. According to the sagas, Erik the Red, outlawed from Iceland, explored Greenland and led settlers there in the late 10th century. Archaeology confirms Norse farms in the southwest, and Norse Greenland lasted for centuries before it faded in the later Middle Ages. Why it ended is debated, with climate, trade and economic pressures all suggested.
North America. The sagas describe voyages to lands called Helluland, Markland and Vinland. For a long time these were treated as legend. In the 1960s excavations at L’Anse aux Meadows in Newfoundland revealed Norse-style buildings and objects, and the site is dated to around the year 1000. It appears to have been a short-lived base rather than a colony. Where exactly Vinland lay, and how many trips were made, remains uncertain.
Why they could go so far
These crossings depended on seamanship. Sailors steered by the sun, stars, birds, wave patterns and landmarks, rather than by compasses, and wide, sturdy cargo ships called knarrs carried families and animals on the long Atlantic runs. The warship design is a separate topic, covered in the context of Viking longships. For exploration, the practical point is that the settlers were experienced at open water, and Iceland and Greenland are visible by stages from one another, with seabirds and cloud patterns offering clues.
Eastward: rivers and trade
Swedish Scandinavians, often called the Rus in eastern sources, moved across the Baltic and up rivers into what is now Russia, Belarus and Ukraine. Light boats could be dragged or carried between river systems, which opened routes toward the Black Sea and the Caspian. Along these routes they traded furs, slaves, honey and wax for silver coins and luxury goods.
Eastern trade left a clear archaeological trace: Islamic silver coins, called dirhams, turn up in large numbers in Scandinavian hoards. Trading centers on the route grew into towns, and the early story of Kievan Rus is tied to these Norse-speaking newcomers mixing with Slavic and other local populations. How large the Scandinavian role really was is a long-running debate, since the local culture became predominantly Slavic over time.
Some of these travelers reached Constantinople, where the emperors valued northern warriors, a tradition that led to the Varangian Guard. The city was known to them as a place of immense wealth, and the Rus both traded with it and occasionally attacked it.
Violence and exploration overlap
Separating exploration from raiding is a modern convenience. A crew might trade where defenses were strong and plunder where they were weak, and the same people sometimes settled afterward. In the east, rulers’ agents collected tribute and goods, which blurs the line again. The most useful view is that “Viking” activity covered a spectrum of overseas ventures, and that exploration and settlement ran alongside the violent episodes described elsewhere.
Evidence and its limits
Much of what we know about Atlantic voyages comes from the Icelandic sagas, which are literary works written in the 13th century or later. Archaeology, place names, written records from other cultures, and coin finds provide checks. Where they agree, the picture is solid. Where only a saga speaks, the details should be treated as traditions rather than established fact.