Gustavus, name of 6 kings of Sweden. Gustavus I Vasa (1496?–1560) was founder of the modern Swedish nation. A Swedish noble, he led the successful revolt against the Danes (1520–23) and was elected king. Instrumental in the establishment of Lutheranism and the growth of the economy, he took firm control of the country and established an hereditary monarchy. Gustavus II Adolphus (1594–1632) reigned from 1611. One of the great generals of modern times, he made Sweden a European power. When he came to the throne, Sweden was at war with Denmark, Russia, and Poland. He ended the Danish war (1613) and the Russian war (1617) victoriously. With his chancellor Count Oxenstierna he introduced wide internal reforms. He joined the Thirty Years' War in 1631, scoring the first Protestant victory at Breitenfeld (1631). He was killed in his victory at Lützen in 1632. Gustavus III (1746–92) became king in 1771, at a time of factionalism and unrest. He regained much of the monarchy's lost power in 1772, and ruled well, introducing many liberal reforms. He was assassinated by a conspiracy of discontented nobles. Gustavus IV (1778–1837) reigned from 1792 to 1809. In 1805 he joined a coalition against Napoleon and lost Swedish Pomerania and territory in Germany; despite English help he lost Finland to Russia in 1808. He was then deposed and exiled. Gustavus V (1858–1950), a popular sovereign, reigned from 1906. Gustavus VI Adolphus (1882–1973) reigned from 1950. He was an able and popular monarch; in 1971 the monarchy was stripped of its powers, but this was deferred during his reign and did not take effect until 1975. He was also a noted archeologist.