When Crown Princess Victoria was born on 14 July 1977, she was simply a Princess of Sweden without any succession rights. Even before her birth, discussions about introducing absolute primogeniture (inheritance regardless of gender) were ongoing in the government. Due to the complicated nature of changing the law, it took until 7 November 1979 for the Swedish Parliament to vote through the amendment to the Constitution which made her heir to the throne. Her younger brother Carl Philip had been born in May 1979, and he was briefly designated as Crown Prince.
The amendment came into effect on 1 January 1980 (40 years ago today), and Victoria was officially designated as Crown Princess. On 9 January, she was also created Duchess of Västergötland.
Absolute primogeniture is now practised by most of the European monarchies. The Netherlands introduced absolute primogeniture in 1983, and King Willem-Alexander’s eldest daughter is also the first woman to carry the Princess of Orange title – reserved for the heir apparent – in her own right, despite the Netherlands’ having had three Queens. Norway followed in 1990 but only for those born after 1990. Crown Prince Haakon’s elder sister Princess Märtha Louise was, however, included in the line of succession. Crown Prince Haakon is followed by his eldest daughter Ingrid Alexandra.
Belgium followed in 1991, for the descendants of King Albert II. King Albert II’s daughter Princess Astrid was also included in the line of succession – having been excluded before. King Philippe’s eldest daughter is Duchess of Brabant in her own right and will be Belgium’s first Queen regnant.
Denmark followed in 2009, having previously followed agnatic primogeniture (male only) from 1853 until 1953. The law was changed in 1953 to allow King Frederick IX’s three daughters to be included in the line of succession. They then introduced male-preference primogeniture, meaning that women could inherit if they had no brothers. This meant that upon King Frederick IX’s death, he was succeeded by his daughter Queen Margrethe II. By 2009 her son Crown Prince Frederik already had a son, and a daughter and the first to be affected by the change in law were his twins born in 2011. Prince Vincent did not gain precedence over his elder sister Princess Isabella.
Luxembourg followed in 2011, having previously followed a line of succession of male-preference among the daughters of Grand Duke William IV – a male-line male descendant of a younger daughter would have had precedence over female descendants of elder daughters. Grand Duke Henri decreed the absolute primogeniture in 2011 and the first to be affected by it were the children of Prince Felix. His eldest daughter Princess Amalia kept precedence over her younger brother Prince Liam. Hereditary Grand Duchess Stéphanie is currently pregnant and her child – regardless of gender – will follow their father as Grand Duke or Duchess of Luxembourg.
The most recent case comes from the United Kingdom and the Commonwealth realms in 2015. In 2011, before the birth of Prince George of Cambridge, it was agreed to amend the male-preference system. The changes took effect on 26 March 2015, and when Prince Louis of Cambridge was born in 2018, he did not take precedence over his elder sister Princess Charlotte.
Several European monarchies still practise male preference primogeniture or bar women complete: Spain (MPP), Monaco (MPP), Liechtenstein (bars women).
Outside of Europe, most monarchies completely bar women from the throne and often they don’t practice a traditional line of succession. Eswatini (former Swaziland – bars women), Lesotho (bars women), Morocco (bars women), Bahrain (bars women), Bhutan (MPP), Brunei (bars women), Cambodia (bars women?), Japan (bars women), Jordan (bars women), Kuwait (bars women), Malaysia (bars women), Oman (bars women), Qatar (bars women), Saudi Arabia (bars women), Thailand (sort of MPP), United Arab Emirates (bars women), and Tonga (MPP).