In this essay Wight clarified the importance of dynastic legitimacy—that is, hereditary monarchy—in European history. In the Middle Ages and subsequent centuries, rulers were mainly princes who inherited their crowns. The principal exceptions were the leaders of republics, including Venice, Ragusa, Genoa, and Lucca in Italy; the Swiss confederation; and the United Provinces of the Low Countries. Dynastic principles included the theory that the ruler was chosen by God through hereditary succession, and that the monarch represented his or her subjects, notably with regard to the official religious denomination of the country. Such principles made dynastic marriages valuable means to provide heirs to the crown, to clarify succession to the throne, to consolidate alliances, to gain influence and wealth, and to legitimize territorial gains. Despite imprudent and egocentric behaviour by some royal leaders, monarchs were increasingly expected to pursue national rather than personal dynastic interests. After the Napoleonic Wars, the Congress of Vienna reaffirmed dynastic principles of legitimacy, including in Venice and the Netherlands; the Swiss confederation was a conspicuous exception. Dynastic rulers have, however, tended to become symbols and instruments of national unity and self-determination. Popular support for dynastic houses has in many cases led to popular legitimacy for constitutional monarchies.