The history of Sweden started to diverge from OTL in 1240, when the Swedes did NOT attack Novgorod, due to the lack of a Mongol attack on Russia. 1288, the island of Gotland became Swedish. From 1319-65, Magnus VII Eriksson was also king of Norway. In 1352, he conquered Skåne (South Sweden) from Denmark; but 1361-64, the Hanseatic League defeated Sweden-Norway in a trade war, which influenced Norway to declare independence again.
In 1426, Birger II Eriksson allied with Boleslaw VI of Poland against the Teutonic Order. 1432 they were victorious; Poland kept its conquests from the last war and also got Wolhynien, Sweden got Estonia (that's only the northern half of OTL Estonia, though).
(Danish) prince Harald had discovered OTL America in 1381. In 1466, the Swedes joined the colonial race, founded Nystad, their first city in Atlantis, at the site of OTL Wilmington, Delaware. They claimed the whole Chesapeake peninsula for Sweden. 1479/80, Sweden made war with Norway, occupied and annexed the Norwegian province of Jämtland.
1504, king Erik XV Birgersson was deposed, for being unpopular and having no heir. Knut Karlsson of the Bonde family was made regent. But 1520, the nobles of Sweden decided to make Henrik VI of Denmark new king, since Knut Karlsson also had no heir. 1523, he also was elected new king of Norway, now reigning all of Scandinavia. Under his rule, the church property was nationalized and the bible translated. But in 1541, all his work fell apart again when his son Gerhard of Denmark, Norway and Sweden was deposed for complete madness. Denmark fell into Civil War, with various (wannabe) contenders fighting; Norway became a nobles' republic again, Sweden declared independence too. With Scandinavia in Civil War / unrest, the other powers used the opportunity: Nystad, the capital of New Sweden, was taken in 1543 by the Dutch; the South and West of the Chesapeake peninsula went to Italia Nuova.
In 1544, the Swedes made Gustav of the Sture family new regent, who managed that the office stayed in the family. But in 1567, his son Sten was deposed after one of his young nephews dies suddenly under unclear circumstances. Instead, Prince Alasdair, already king of Scotland, Ireland, Denmark and Norway, became king of Sweden, thus forming the second Scandinavian Union. After his death in 1588, his vast lands were divided: Scotland and Ireland went to his elder son Alexander V, Scandinavia to his younger son Christian / Kristian.
Only a few years after, in 1592 Vladimir-Suzdal attacked Sweden. In the peace of Vanhakaupunki 1594, Scandinavia had to give Estonia and parts of Finland to Russia. The nobles of Sweden became discontent and deposed king Kristian in 1595, electing Albrecht / Albert of Mecklenburg new king. Thus, Sweden now became entangled in German affairs.
Under king Alexander, an expedition with a mixed Scandinavian crew under a captain Ingolfsson had gone to Africa in 1569, reaching Cape of Good Hope. They liked the climate and told the king on their return about it. 1574, they founded the colony of Australafrica (Australia for short) with the capital Alexandersborg (OTL Cape Town). 1582, Scandinavian explorers discovered Madagascar; 1588, Zanzibar}}. But 1594, with Scandinavia in trouble, the Dutch used the opportunity and occupied Australia. But as soon as 1600, the Revolt of the "Söderlinger" (Scandinavians in Australia) against the Dutch started. And 1615/16, in the "Australian War" Sweden defeated the Dutch, took back Australia. 1626, Scandinavians from Australia reached India; during the 1630s, Swedes visited and learned about the various kingdoms in SE Asia and the Indies; 1649 (3346, Yin Earth Ox in the Chinese calendar), Swedish traders arrived in Canton. In 1644, Swedes even discovered the west coast of OTL Australia, but weren't interested in that continent either.
1600, Erich / Erik XVI became new king in Sweden. He made many important reforms in the state, especially the army. As a result, in the first Nordic War 1607-11, Sweden defeated Denmark-Norway, took Göteborg, Trondheim and Narvik.
In 1640, King Erik XVII of Sweden, Northern Norway and Mecklenburg founded the Baltic League with Prussia, Brandenburg-Silesia and Franconia-Pomerania against possible Polish or Russian threats; but it became directed against France as well.
As a part of these anti-French politics, in 1657 Sweden agreed to give back Braseal (which they had occupied in 1633, for fears that France might grab the colony) to England, in exchange for an alliance.
Queen Kristina I, one of the most famous women in history, won Spain and the Netherlands (the latter by her marriage to prince Eduard of Wassenberg) for the anti-French alliance. When Sicily joined the alliance too, the anti-French War broke out in 1682. Being victorious, in the peace of Amsterdam 1694 Denmark's part of Norway became Swedish.
Union with the Dutch
After the death of king (and Roman emperor) Eduard IV in 1722, the Netherlands were united in personal union with Sweden-Norway-Mecklenburg under his grandson Erik XVIII. France objected the unification, so Sweden had to defend itself in the Dutch War of Succession.
1726, Olof Tiselius started his first serve as First Minister of Sweden. After the Netherlands (which already had a constitutional government), during his time Sweden-Norway-Mecklenburg also saw a shift of power: Away from the king, to Riksdag (parliament) and First Minister.
Sweden was still engaged in colonial affairs, like getting influence in the Kongo kingdoms or backing Vijayanagar in the Indian War. 1738, Swedes took Sri Lanka, after defeating a stronger French fleet surprisingly. On the other hand, in the Madagascar War between Sweden and Persia 1749, Persia took the island.
Sweden-Norway-Netherlands also fought in the Palatinate War of Succession against France.
1759, the first telegraph was built in Sweden.
Sweden also joined the first and the second French Republican Wars for the monarchist cause, but this cost them eventually the Netherlands and Mecklenburg. 1785-87, Novorossiya attacked the weakened Sweden, conquered Finland, Estonia back.
Now Sweden joined France in a secret alliance, because now even king Johan II doubted the cause of the Royalists. In the third French Republican War, they conquered all of Denmark (which is why this war was also called the third Nordic War). As a revenge, the Brits took Sri Lanka, however.
1830, a Swedish ship coming from Australia (OTL South Africa) discovered Antarctica.
| Prominent Rulers|
(founding members in italics)