Once the Skræligen Þing signed their oath of fealty to King Christian IV, they held a feast for the expedition and celebrated the beginning of a new future. After a few days of recovery and restocking, most of the Danes made the journey back home, although 22 elected to stay in Skrælige. In early 1599, an additional 100 arrived, along with the new colonial governor, Egil Christiansen. The first priority was to begin recording the current state of Skrælige, which meant commissioning a "Folketælling" (i.e. Manntal). This was completed by 1600, and the results were as follows:
Skrælingborg: 472 (-28), incl. 55 Danish immigrants
Church & Market District: 172 (-10), incl. 13 Danish immigrants
Midtvej & Nyhavn (Formerly Miðrway & Nyjahofn): 237 (-), incl. 42 Danish immigrants
Outside of the walls: 49 (-15)
Venstrevej (formerly Vinstrileið) village: 14 (-3)
Nyhåber (formerly Nyrvænn): 150 (-15), incl. 24 Danish immigrants
Main Village: 127 (-5), incl. 24 Danish immigrants
North Village: 10 (-5)
South Village: 13 (-5)
Midtunge (formerly Miðrtunga): 42 (-2), incl. 8 Danish immigrants
Nordsted (formerly Norðstaðr): 61 (-2), incl. 16 Danish immigrants
Eirsten (formerly Eirsteinn): 55 (-1), incl. 15 Danish immigrants
Abenakiborg: 10 (+2), incl. 2 Danish immigrants
Lillebugt (formerly Smarvik): 35 (+3), incl. 10 Danish immigrants
Rasbøje (formerly Rasbeygja): 0 (-21), abandoned after nearly being wiped out by smallpox
Midtsunborg (formerly Miðrsunborg): 21 (-1), incl. 2 Danish immigrants
Total population of 846 (-65), including 122 Danish immigrants.
The first big change for Skrælige was religion. The Protestant Reformation had spread throughout Europe in the 16th century, including Denmark-Norway. Denmark and Norway themselves converted their state religion to Lutheranism in 1536 and 1537, and the last part of the realm to convert was Iceland, which did so 1539-1550. Skrælige was still Catholic, although its isolation meant that its doctrines weren't 100% in line with the Papacy. Until coming under the Crown of Denmark in 1598, the ideas of the Reformation hadn't really made it into Skrælige, as the limited contact to the Old World was via Spanish trade.
Incorporating the Lutheran doctrines into the church of Skrælige went more smoothly than most conversions in Europe - Skrælige had been separated from any real papal control for so long that there was not much reason for opposition. The main change was in language - what little Latin had been used was now all gone, replaced with Danish & Skræligen. A few Danish Bibles were brought over, and work began on a Skræligen translation. (This was largely based on the Icelandic translations, as that was the most similar language at this point.)
Real conflict began in 1600 after the Folketælling was completed. With a thorough compilation of all property on the islands recorded, governor Egil Christiansen seized all church property on behalf of the King. Most of the churches on the islands reluctantly agreed, but the archbishop Jensi Karlsson fled across the Siguan River to the church in Nordsted (Norðstaðr). The fight with Danish officials carrying out the seizure led to the burning of the church, as well as the execution of the archbishop Jensi Karlsson.
While the imposition of Lutheranism was only strongly opposed by a small minority, the next royal act became much more controversial. After imposing a Danish monopoly on external trade in Iceland in 1602, Denmark enacted a similar set of laws for Skrælige. All trade would be controlled by the family of Karl Valtersson, a prominent merchant who was friendly with Governor Egil, and would only go straight to Copenhagen. As an effect of this, all trade with the Spanish territories was banned. This transition was painful - for nearly a century, the only external trade was with the Spanish territories. Now all trade had to make the much more arduous journey east across the North Atlantic, and wasn't even under Skræligen control anymore.
While some smuggling south did occur, Skræligens didn't really have a choice but to comply. After all, being part of Denmark's empire was supposed to bring them prosperity, and this was the necessary cost of business. However, over time more European colonies were founded nearby. (See European Colonisation below.) Even though these new colonies were much closer, trade with them was still illegal. Despite bringing this up with the crown several times, no allowances were made for this local trade, building resentment among the Skræligens.
The governing of Skrælige was no longer solely for the benefit of Skrælige, but for the benefit of the crown of Denmark. In fact, Skrælige's needs were barely considered beyond what was needed to enrich Denmark, and the Þing was reduced to a symbolic role. This change was quite a shock to Skræligens who were used to at least being listened to, even if the important leaders in the Þing did tend to be better off than the general population. The new leadership presented an ideological conflict between the self-governing group leadership of the old Skrælige and the Absolutism of Denmark, which showed no signs of going away any time soon.
Over the next few decades, European powers began to colonise nearby lands. After an unsuccessful attempt at settling on St. Croix Island in 1604, the French founded Port-Royal on modern day Nova Scotia the next year. After an English attack in 1613, Port-Royal was temporarily abandoned, but later moved upstream. (Today it is now known as Annapolis Royal.) This part of New France became known as Acadia, and eventually expanded to the other side of the Bay of Fundy around modern day St. John, NB.
English settlement was a lot closer to Skrælige, including the failed Popham Colony in 1607 which was just across the Norþæn Strait from the islands of Skrælige. The first successful English settlement nearby was Plymouth in 1620. More settlements soon followed, the main "first" settlements are labeled above. By the 1630s English settlements stretched north to the other side of the Skræligen Sea. There was minimal conflict however - construction of fortifications in Skrælige (see Christianborg - Danish Military Fort in Skrælige below) was enough to ward off any English raids. However, the charter for the Massachusetts Bay Colony was unclear on whether it claimed Skrælige for itself - the Mass. Bay government claimed that the islands were in fact part of the colony, and this uncertainty loomed over the islands.
The new immigration and leadership of Skrælige meant a lot of new construction as well. Most of the "urban" buildings in Skrælige were built in the 14th century or earlier - demand for housing disappeared with the Isolation and the migration into the surrounding countryside in the 15th century, and subsequently plummeted with the introduction of European plagues in the 16th century. Along with new half-timbered construction, new architectural styles arrived as well. Tall Baroque buildings, often referred to as "Copenhagen houses" in Skrælige, stood out with their bright colors among the more subdued whites and browns of the older constructions.
One major new landmark in Skrælingborg was the Governor's residence, built between the church, the old Great Hall, and the Þing building. Completed by 1603, this was now the clearest sign of Denmark's presence in Skrælige. The structure holding the Þing had already been dwarfed by other buildings in the city, but was now further dwarfed by the new seat of power. While the residence was not substantially larger, it was much more ornate and modern. In comparison, the Þing began to look dilapidated, and the crown had no interest in preserving the building representing potential competing interests.
The last new construction of note was a new church in Nordsted after the burning of the old church in 1600. After many delays, this church was completed by 1619. Now the largest church in Skrælige, the Bishop of Skrælige (the head figure of the church in Skrælige) moved across the Siguan River to Nordsted.
The most significant construction project during Danish rule was the star fort of Christianborg, named after Christian IV. The existing fortifications on Skrælige were designed for protection against the Abenaki, and were not suited to defending against the European powers moving in nearby. Initial fortifications were built at the mouth of the Siguan River in the early years of Danish rule, but the outbreak of the Thirty Years' War demonstrated that more substantial fortifications might be required. Construction of Christianborg began in 1625, and the final structures were completed by 1630. The fort never actually saw battle though, instead just warding off any potential attacks. All of the Danish warfare was instead limited to the European continent, to the relief of the Skræligens.
The construction of Christianborg was not the only Danish military action in Skrælige. In 1632 they launched a "scouting party" inland into the interior of the island, to scout out defensible areas to expand to. It would be more accurate to call it an invasion of the Siguan River Valley though, the "scouting party" was not even pretending to try to exist peacefully with the Abenaki. Many were killed, and a new village of Egilsted was founded on the ruins of an Abenaki village.
Controversially, many Abenaki were kidnapped into slavery as well. Slavery hadn't been present on the island for centuries, and the capture of slaves during war was no longer practiced either. However, this was common practice on the mainland English colonies, and the Danish authorities saw no reason to not do the same. This was probably the beginning of the modern Skræligen abolition movement as well - while the Skræligen locals had no power to stop this at a government level, a significant number of Abenaki slaves escaped with the covert help of locals.
Given the likelihood of Abenaki slaves to escape, the market shifted to importing African slaves instead. The first documented trade of an African slave in Skrælige occurred in 1639, one year after the first African slaves were traded in New England in the Colony of Massachusetts Bay. While Skræligens had lived alongside Abenaki in the past, and there was a small amount of mixing between the two cultures, this was not the case of African slaves. It was easy to drive up opposition to Abenaki slavery for these reasons, but while African slavery was not popularly supported, it was not strongly opposed either.
Over in Europe, the Thirty Years' War was devastating the continent. What originally began as a religious conflict between Protestants and Catholics within the Holy Roman Empire eventually morphed into a massive conflict throughout the continent, no longer strictly on religious lines. Denmark intervened from 1625 to 1629 against the HRE, and was involved again from 1643-45 when the Swedes invaded Denmark in the Torstenson War. The conflict concluded for Denmark in 1645 with the Peace of Brömsebro, which transferred some Danish land to Sweden.
As part of the peace treaty, Skrælige was also given to Sweden, and would now be administered as part of New Sweden (Nya Sverige). This was hard to get used to for Skrælige - for the first time, their rulers changed without them having any say whatsoever. Still, they were hopeful that a government based closer to home in Fort Christina (present day Wilmington, Delaware) would allow them more autonomy.
The Danish here is modern Danish - as far as I'm aware the language at the time was not radically different from modern Danish, the same way Shakespearean English isn't radically different from modern English, but I could be wrong here. Not every town name has been directly translated - some have, some have just been altered to sound more Danish, and others haven't been changed.
The "Copenhagen houses" seem to have mostly been built in the second half of 17th century in Nyhavn, Copenhagen. I stretched them back a little to fit into Skrælige since I like the style a lot, so that's not 100% historically accurate. The height difference isn't a thing in real life as far as I know, but it is in Cities: Skylines since the assets are scaled differently by different creators.
I originally planned on handing Skrælige over to the English in the Peace of Westphalia in 1648, so if there's any references to 1648 left that's why. However, the more I thought about it, the more it didn't quite make sense - hence Nya Sverige instead.