Charles X Gustav of Sweden in the context of "Throne name"

A regnal name, regnant name, or reign name is the name used by monarchs and popes during their reigns and subsequently, historically. Since ancient times, some monarchs have chosen to use a different name from their original name when they accede to the monarchy.

The regnal name is usually followed by a regnal number, written as a Roman numeral, to differentiate that monarch from others who have used the same name while ruling the same realm. In some cases, the monarch has more than one regnal name, but the regnal number is based on only one of those names, for example Charles X Gustav of Sweden. If a monarch reigns in more than one realm, they may carry different ordinals in each one, as some realms may have had different numbers of rulers of the same regnal name. For example, the same person was both King James VI of Scotland and King James I of England.

Katarina kyrka (Church of Catherine) is one of the major churches in central Stockholm, Sweden. The original building was constructed 1656–1695. It has been rebuilt twice after being destroyed by fires, the second time during the 1990s. The Katarina-Sofia borough is named after Katarina Parish and the neighbouring parish of Sofia.

Construction of the church started during the reign of Charles X Gustav of Sweden, and the church is named after Princess Catherine, mother of the king, wife of John Casimir, Palsgrave of Pfalz-Zweibrücken and half-sister of Gustavus Adolphus. The original architect was Jean de la Vallée. The construction was severely delayed due to shortage of funds.

The Northern War of 1655–1660 was fought between Sweden and the Polish–Lithuanian Commonwealth, with participation at different times by Russia, Brandenburg-Prussia, the Habsburg monarchy, and Denmark–Norway. It ended with the treaties of Copenhagen and Oliva in 1660.

In 1655, Charles X took advantage of the Russo-Polish War (1654–67) to over-run western Poland. The Grand Duchy of Lithuania was annexed by Sweden, and John II Casimir Vasa took refuge in Vienna. He managed to regain parts of his kingdom in 1656, and the conflict widened when Russia declared war on Sweden, supported by Emperor Leopold and Frederick III of Denmark.

From 1611 to 1721, Sweden was a European great power, becoming a dominant faction in the quest for control of the Baltic Sea and a formidable military power. During this period, known as Stormaktstiden ('The Great Power Era'), the Swedish Empire held a territory more than twice the size of its modern borders and one of the most successful military forces at the time, proving itself on numerous occasions on battlefields such as Wallhof, Narva, and Düna. The military of the Swedish empire is commonly (and wrongfully) recognized only as the Caroleans, which were in fact not in service until the late 17th century under Charles XI and his successor. The Swedish Empire and its modern military force was founded by Gustavus Adolphus, who inherited the throne in 1611 at age 17. He immediately reformed the common European military based on mercenaries to a professional national army. However, before completing his vision of conquering the Holy Roman Empire, the warrior king was killed in action in 1632. His daughter and successor did little to improve Sweden's military position and abdicated early, providing the Swedish Empire with a more warlike ruler. Charles X Gustav was only king for 5 years, but conquered large amounts of territory that still belong to Sweden today (including Blekinge, Bohuslän, Skåne, and Halland). His son Karl XI would further strengthen the army by introducing the Caroleans, which were also used by Karl XII in the Great Northern War.

However, despite great successes on the battlefield, an inadequate economy and limited manpower eventually led to the demise of the Swedish Empire, which ended its 110-year period as a great power in 1721.

Alexander Cooper (11 December 1609 – 1660) was an English Baroque miniature painter.

Catherine of Sweden (Swedish: Katarina; 10 November 1584 – 13 December 1638) was a Swedish princess and a Countess Palatine of Zweibrücken as the consort of her second cousin John Casimir of Palatinate-Zweibrücken. She is known as the periodical foster mother of Queen Christina of Sweden and the mother of Charles X Gustav of Sweden.