This is the timeline for the Midnight Sun TL.
In 1430, the Greenland Norse were pushed to the edge of starvation by worsening climactic conditions and hostile Inuit, abandoning their Western Settlement to withdraw to the very southern tip of Greenland. The trading ships had long stopped coming, and Norse farming techniques, ineffective in greenland's climate, were pushing them into starvation. After the daughter of a major chief, Jon Arnason, starved to death, he realized that the colony would be destroyed unless serious action is taken. He ordered his men to begin large-scale fishing in an attempt to utilize a new food source. After Arnason survived the winter in a far greater state of comfort than his non-fishing compatriots, they also adopted fishing. As there was a shortage of boats to fish from, or timber to build new boats, the Norse for the first time offered to trade iron for Inuit kayaks. The Inuit accepted, and a trading post as set up at the former Western Settlement.
In 1432, Arnason's son Einar was stranded at the Western Settlement over the winter, but is fortunately taken in by the Inuit. He acquired a working knowledge of their language, and married an Inuit woman. Meanwhile, the Eastern Settlement began hunting whales in line with Inuit custom, enabling them to gain a supply both of food and fuel. Several Norse overwintered at the Western Settlement the next year, where Einar Arnason's first child, a daughter named Freydis, was born. The Inuit are able to make a much larger and more successful hunt using iron tools, and requested, through Einar, that a blacksmith be sent to the Western Settlement.
By 1434, the Western Settlement had expanded into a joint Inuit-Norse community of around 60 people. The Inuit began to adopt iron tools on a larger scale, and produced larger kayaks carrying two to three passengers. After the death of the Inuit chief at the Western Settlement, or Ivituut, Einar Arnason was made the new chief by acclamation. The last cows died out in southern Greenland after fodder proves inadequate. Only sheep, goats, horses and dogs are left to the Norse.
In 1435, the main hay barn burned down at the Eastern Settlement, starving about 90% of the livestock. The people begin to starve also, and attack the richer farms, killing much of their breeding stock. Jon Arnason is one of the dead. Some hundreds trek over southern Greenland to Ivituut, but most die on the way.
An expedition from the Western Settlement reached the Eastern one the next summer, finding only a few thousand people still alive. Most were evacuated to the Western settlement, leaving only around a thousand. After they requested more hunters, several dozen Inuit move south to the Eastern settlement, greatly enhancing its food production capabilities.
Over the winter, the last priest consecrated by the last bishop sent from Europe died. Several dozen Norse objected to the fact that no baptism, absolution, or other religious ceremony can now be carried out. Some left in two of the last remaining ships for Europe. They were never heard from again, and were presumably killed by the impassable conditions in the North Sea. After a glacier cut off the fjord at the Western Settlement, Einar Arnason ordered the community, now numbering around 500, transferred wholesale to the Eastern Settlement. The Inuit inhabitants also moved.
In 1439, several hundred Inuit arrived at the Eastern - and now only- Settlement to trade. Some stay there, and took up sheep farming or acted as hunters for the less competent Norse. Some of the poorer Norse returned north to the Inuit, judging it better to be well-fed barbarians than starving civilized people.
The next year, a Norse woman who lived with an Inuit man was=s kidnapped by her disapproving father. Her husband responded by impaling him with a harpoon, but was promptly lynched by an enraged mob, threatening to ignite ethnic strife. Einar Arnason responded by denying all participants in the conflict, access to communal food supplies until they reconcile, ending the conflict quickly. Nonetheless, internecine conflict became an increasing threat.
Destabilization, 1441 - 1450
In 1441, both Inuit shamans and religious members of the Norse united to condemn increasing "corruption" of their values by interaction with the other culture. They argued in favour of ending cohabitation at the Eastern Settlement and at other shared outposts along the south coast. However, both benefit too much from the other and mainstream members of both societies condemn the idea. The Norse began around this time to adopt shamanic rituals and Inuit superstitions, while the Inuit adopted parts of Christianity. The Church is massively undermined by the lack of any bishop consecrated in Rome. Another voyage to Iceland was attempted, but the ship broke up in the sea ice in sight of shore. One Norseman captures several caribou, and attempted to tame them. He was moderately successful, and is able to keep the half-tame caribou through the winter. His neighbours immediately adopted the idea.
In a desperate attempt to preserve societal stability, Einar Arnason ordained a bishop himself, declaring him Bishop of Greenland and giving him the authority to ordain future bishops. The bishop promptly consecrated forty new priests. Conservative Greenland Norse rejected the new Bishop, especially when he adopted several Inuit customs, and killed several of the priests. Many Norse eagerly accepted the priests, and thousands are baptized or married "properly". In response, the conservative Norse launched a second voyage to Iceland, returning with their own, supposedly pope-ordained, Bishop. Many suspected the ship did not reach Iceland, and the bishop is, in fact, a fake. He was promptly denounced as such by the first bishop, triggering an ecclesiastical struggle, termed "the War of the Two Bishops".
In an effort to appeal to Inuit, the first bishop increasingly diluted his church with Inuit customs and ideas. The more conservative church responded by denouncing him as a heathen.In 1444, after the failure of the seal migration triggers widespread hunger, both bishops declared it divine retribution for the other's sins. Rival priests begin arming themselves, and fighting raged between the two camps, referred to as the Eystri and Vestryi, referring to the geographical location at which the two groups are concentrated. The more liberal immigrants from the Western Settlement largely supported the first bishop, while the Easterners supported the second.
On the night of New Year's, as the first Bishop held a late mass in the cathedral at Gardar, several dozen of the Eystri surrounded the church. They then set it aflame. The Bishop burned to death, along with most of his priests and congregation. Immediately, the second Bishop proclaimed that God had clearly spoken; as the sole remaining religious authority, he must also be the legitimate one. The same night,which would eventually become known as Bloody Sunday, Einar Arnason's son Thorfinn was born.
Many Norse now shifted their allegiance to the surviving Bishop. Others, however, rejected the Church outright, shifting to shamanism or returning to pagan worship. The Bishop called the first meeting in almost thirty years of the Greenland Assembly, or Althing, in 1446, to discuss several pressing issues. It almost immediately broke down. The tradition of the Althing was that all significant chiefs be allowed to speak and have a vote, but the conservative Norse refused to admit Inuit chieftains. The Bishop called for the chiefs to enforce obedience to the Church's decrees, but this was in turn blocked by the Vestryi faction. The Althing deliberated on-and-off for two years before being officially broken off.
It was at this time that a major epidemic of smallpox struck the Inuit portions of the population. Thousands died, and many more fled Greenland for Markland to the west. To general horror, the epidemic seemingly afflicted the Marklanders far worse. The northernmost island of Markland, OTL Ellesmere Island, was virtually depopulated, and the disease spread even farther south. In Greenland, it ran its course within a year, leaving the Inuit population halved to around 12,000. The balance of power on the island now shifted significantly toward the Norse.