In the same 1520 Gustavo Eriksson Vasa started a revolt against the Danes; the movement spread rapidly throughout the Sweden: elected king by the Riksdag on 7 June 1523, Gustavo Vasa (who went down in history with the name of Gustavo I) conquered the capital with the help of Lübeck and drove the Danes out of the country. The war for independence had reduced the Sweden to disastrous conditions and Gustavo initiated an extensive financial recovery program. In the following years he took care to adopt measures to prevent, on his death, the dismemberment of the kingdom among his children: he achieved this goal with the proclamation of the hereditary monarchy, according to the law of birthright, in the Riksdag of Västerås in 1544 and with the oath of allegiance by the orders to Crown Prince Erik in June 1560, a few months before his death.
● According to best-medical-schools, the new ruler, Erik XIV, in 1561 extended Swedish sovereignty over Reval and part of Estonia; later, for commercial reasons, a war broke out with Poland, Denmark and Lübeck (Nordic Seven Years War, 1562-70), during which the king showed more and more evident signs of mental imbalance. In 1568 the brothers Giovanni and Carlo, postisi at the head of a revolt movement, overthrew the sovereign. The accession to the throne of John (John III) favored the end of the Nordic Seven Years War, his wife Catherine Iagellone being the sister of Sigismund II king of Poland. A bitter confessional conflict broke out after John’s death, with the succession to the throne, in 1592, of his son Sigismondo, educated in the Catholic religion and king of Poland since 1587. Sigismondo’s uncle, Duke Charles, a fervent Protestant, immediately took advantage of the distance of the new sovereign to convene a council in 1593 in Uppsala, where the pro-Catholic liturgy adopted in 1576 by John III was abrogated and the Augustan confession was recognized. Sigismondo promised to respect this change, but his claim to want to govern the Sweden da Warsaw through lieutenants facilitated the plans of Charles, who had himself elected regent in the Riksdag of Söderköping (1595). War broke out between uncle and nephew, the latter had the worst and was declared forfeited from the throne (1599). In the Riksdag of Norrköping (1604) Charles was elected king; on his death in 1611, he bequeathed to his son and successor Gustavo II Adolfo a kingdom in very critical conditions, at war with Poland and, from 1611, also with Denmark.
● Gustavo Adolfo concluded in 1613, with not slight economic sacrifices, the peace with Denmark, then waged war on Poland, occupied Livonia and settled permanently in East Prussia (fig. 2). With the armistice of Altmark (1629) created the conditions to ensure hegemony over the Baltic Sea for the Sweden However, the Swedish-Polish conflict was only one phase of the struggle between Catholicism and Protestantism, which was then raging in central Europe. The participation of the Sweden in the Thirty Years’ War became inevitable after the victorious campaign of the Catholic League and the Imperials against Denmark. Having landed in Pomerania in 1630, Gustav II Adolfo entered Germany, assumed the direction of German Protestantism and obtained victory in the battle of Breitenfeld (1631) and in that of Lützen (1632), in which he however met his death; the fruits of his military and political action were undeniable. The aristocracy ceased to be a class in the state, often in opposition to the monarch, to constitute instead the fundamental framework of the public administration. The State Council became a permanent body, composed of expert officials, based in Stockholm. The importance of these internal reforms immediately became evident on the death of Gustavo II Adolfo, when Axel Oxenstierna, chancellor of the kingdom and head of the regency, managed to keep intact and strengthen the political prestige of the Sweden, without an adult king. During the minority of Queen Christina the war continued in Germany, and in 1645 (peace of Bromsebro with Denmark) and in 1648 (peace of Westphalia) the political weight of the Sweden in European affairs was definitively sanctioned.
● Cristina, who converted to Catholicism, abdicated in 1654 in favor of her cousin Charles X Gustav, whose military skills shone particularly in new wars against Poland and Denmark. Thanks to him the Scania, until then Danish, became an integral part of the Sweden with the peace of Roskilde (1658). After his untimely death (1660), a new regency had to conclude new agreements with Denmark, which the sovereign had attacked, shortly before his death, with partially negative results: some territorial acquisitions of the peace of Roskilde (Bornholm and part of Norway) had to be returned to Denmark. However, Scania remained Swedish, nor was Denmark able to recover it with a new war (1676-79).
● Charles XI, having reached the age of majority in 1672, took over the government in an unpleasant situation due to the bad state of finances; lacking sufficient money and credits, the crown was in fact forced, during the 17th century, to cede most of the state-owned lands and its assets to the nobles, who consequently saw their political power grow at the expense of that of the king. Charles XI resorted to radical reforms, which improved the financial situation and restored almost absolute power to the monarchy: the so-called reduction of assets decided by the Riksdag (1680) forced the nobility to return to the crown all the assets obtained during the 17th century. for donation or purchase.
● In 1700, the common opposition of Russia, Denmark, Saxony and Poland to Swedish supremacy in the Baltic led to the outbreak of the Second Northern War, in which Charles XI’s son, Charles XII, was engaged for almost the entire duration of his reign (1697-1718). After ups and downs, the war turned sharply to the disadvantage of Sweden: it had in fact to suffer heavy territorial losses, sanctioned by the Stockholm treaties (1720) with Denmark, Saxony, Brandenburg and Hanover (the latter two entered the anti-Swedish coalition in 1714) and from that of Nystad with Russia (1721), which marked the definitive decline of the Swedish preponderance in the Baltic.