the end of the Viking age came when the Norwegian forces lost the battle of Stamford bridge

"Viking Age" itself is a histriographical concept of periodization, with different definitions.

• In Scandinavia, archaeologists have traditionally employ this term to describe the last phase of their Iron Age before the establish of medieval kingdom as well as the arrival of written records. They also pay not so much attention to reach an agreement on the exact lower period limit (terminus ante quem) of this period: While Norwegian histriography sometimes puts an emphasis on the year 1030, not 1066, when King Olaf Haraldsson (St. Olaf) who played an central role in the Christianization of the country died in the battle of Stiklestad (Cf. Krag 2000: 28), some Swedish scholars only roughly set the limit to about 1050/ 1060/ 1100 (Haraldsson 2007 (1995): 19f.).
• As I made a note before in: After the end of the viking age in 1066, what happened to the term ’to go viking’?, the year 793 (raid in Lindisfarne) and 1066 (the battle of the Stamford Bridge) certainly symbolize the rise and the fall of the viking (in the sense of raiding) activity, but not definitely the exact start/ end date of the raid. As I made a brief list in Has Norway invaded England since 1066, Norwegian rulers sometimes led the expedition into the British Isles well after 1066, and both King Svend Estridsen of the Danes (d. 1076) and his son Cnut the Holy (d. 1086) even landed in eastern England in person in the 1070s to collaborate with English rebels against William the Conqueror.

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As for the general decline (out-of-trend) of the raiding activity of the Scandinavians, however, scholars can propose some more contributing factors, though all of them are of highly hypothetical nature:

• Running out of the large-amount silver inflow from Russia/ Central Asia in the middle of the 10th century
• The establishment of larger polity across Western Europe, with better defending measures
• From Viking to Crusader: While the Christianization seemed not to discourage the raid and the violence against the Christians or church institutions much in a short-term, it provided the Scandinavian ruling elites with another destination to gain prestige in the 12th century. Armed pilgrimage, or the expedition into the Holy Land was certainly not lucrative in material wealth, but they could earn the fame both in their homeland (as successful commanders of the expedition) and in European neighboring powers (as zealous newcomers to the emerging Latin Christendom). Until then, one of the chief motives of raiding had been the chieftain's political economy - both success of raiding and the distributed loot was useful for the chieftain (local magnate) to establish himself as a famed leader to his retinue. On the other hand, "The (Northern) crusade" into their former neighbors might also offer them more material profit like the land and the loot, with the official sanction of their new Christian acquaintances.
• Intensified new land use especially in the inland area

Taken these elements together, we can say that the main source of the ruling elites' power somehow shifted from the silver (either earned by the raid or the trade) to the more stable form of the wealth like the the extensive land use in course of the 11th to the 13th century, I suppose.

Note that the exact primary focus on individual researchers on the contributing factor(s) in fact varies. To give an example, Bagge compares the general circumstances of the 11th century Norway with emerging new polities in about contemporary East-Central Central Europe like Poland and Hungary. He suggests:

"..... [now] the only way for ambitious chieftains to gain wealth and power was within Scandinavia. In the case of Norway, this period coincided with large part of the aristocracy and the people rallying around indigenous kings who resisted Danish dominance (Bagge 2010: 35)."

His summary of the outline also states (Bagge 2010: 39):

• Viking and trading expeditions provided the elites with the surplus to be invested for the political power at home
• The political pressure from Germany, the powerful Christian neighbor, instigated the political unification first in Denmark, then in two other kingdoms
• The subsequent establishment of three Nordic kingdoms was primarily a result of the power competition in Scandinavia.
• (Christianity worked there as an instrument of the monopolization of political power as well as the incentive to expand)

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As for the continuing practice of raiding on now Christian pretext other than the Vikings, I suppose the case of King Sigurd the Jerusalem-Farer (d. 1130)'s Kalmar expedition in 1123 or 1124 was the most telling one. King Sigurd the Jerusalem-Farer of Norway, who had became also famous across Europe due to his crusade to the Holy Land from 1107 to 1111, led the expedition into Småland (now SE Sweden), originally planned as a joint expedition with King Niels of the Danes (d. 1134). Later saga author narrates his action as following:

"King Níkolás [Nils] sent word to King Sigurðr Jórsalafari (Jerusalem-Farer) and asked him to give him troops and every kind of support from his kingdom and go with King Níkolás east past Svíaveldi to Smálǫnd to Christianise people there, as those that lived there did not observe Christianity, though some had accepted Christianity. At this time widely in Svíaveldi many people were heathen and many poorly Christian.....[they= the Norwegian fleet] made their way after that east to the market town that is called Kalmarnar, and raided there and also on Smálǫnd, and exacted a payment in food from Smálǫnd, fifteen hundred cattle, and the Smálendingar accepted Christianity. After that King Sigurðr turned his army back and came into his kingdom with many very costly things and items of value that he had gained on this journey, and this expedition was known as the Kalmarnar expedition (Magnússona saga, Chap. 24. The translation is taken from: [Finlay & Faulkes trans. 2015: 161]).

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Concerning the land use during and after the alleged Viking Age, the development of the settlement archaeology and place name study in the late 20th century has offers main clues to us.

The settlement structure of Iron Age Scandinavia (including the Viking Age at its later phase) had not been stable, and the excavation of some settlements like Vorbasse (linked to the English introduction of the village) in central-southern Denmark (Jylland) shows repeated re-location of the buildings/ settlement around there. After the 11/12th centuries, however, medieval settlement (with the Romanesque church) formed and the settlement structure basically continued unchanged into modern period (Douglas Price 2015: 262-66, mainly based on Hvass 1983). This new village consisted of seven large farms of quite different sizes that suggests the hierarchization of power and wealth. The largest farm, also with the smithing workshop, could have about 100 domestic cows and horses, and was about twice as large as other farms in the settlement. In other words, post-Viking (Iron) Age lordship evolved around 1100 has determined the basic social order of the settlement since then.

The new settlement established in the 11th/12th centuries, however, is often located in hitherto un-occupied but suitable for arable farming (Sawyer & Sawyer 1993: 45). The historical place name can be a bit tricky (since they sometimes probably have first been confirmed in the documentary evidence more than a few centuries after it got the place name), but the smaller Scandinavian farms with suffixes like -garðr, -hus, -tun, -ruð, -reitr, -holt, -leið, -þorp, -kot, -brenna, -hagi, -gerði, often found in marginal locations, are often supposed to have been founded from the 11th century to the large-scale farm abandonment mainly caused by the Black Death. A scholar calculates that about 10,000 farmsteads with such names could have newly been founded in Norway by the beginning of the 14th century, and its amount indeed roughly corresponded with the half of the total farmsteads, especially in Eastern inland Norway (Moseng et al. 2007: 99).

References:

• Finlay, Alison & Anthony Faulkes (trans.) Heimskringla, iii. London: Viking Society for Northern Research, 2015.

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• Bagge, Sverre. From Viking Stronghold to Christian Kingdom: State Formation in Norway, c. 900-1350. Copenhagen: Museum Tusculanum, 2010.
• Douglas Price, T. Ancient Scandinavia: An Archaeological History from the First Humans to the Vikings. Oxford: OUP, 2015.
• Gustafsson, Harald. Nordens historia: En europeisk region under 1200 år. 2. oppl. Lund: Studentlitteratur, 2007 (1. oppl. 1995).
• Hvass, Steen. "Vorbasse." Journal of Danish Archaeology 2-1 (1983): 127-136. DOI: 10.1080/0108464X.1983.10589898
• Krag, Claus. Norges historie fram til 1319. Oslo: Universitetsforlag, 2000.
• Lund, Niels. 'The Danish Empire and the End of the Viking Age.' In: The Oxford Illustrated History of the Vikings, ed. Peter Sawyer, pp. 156-81. Oxford: OUP, 1997.
• Moseng, Ole G. et al. Norsk historie, i: 750-1537. 2. utg. Oslo: Universitetsforlag, 2007.
• Sawyer, Birgit & Peter H. Sawyer. Medieval Scandinavia: From Conversion to Reformation circa 800-1500. Minneapolis: U of Minnesota Pr., 1993.

(Edited): fixes typos, with uniform translation of moniker.