It's also clear that the king treated his son's children differently in terms of dukedoms than his younger daughter's children. While especially Carl Philip's eldest child (the rightful heir in CG's eyes?!) got ducal titles with a lot of history (and
a palace attached to it). Madeleine's childeren (just like their mother) mostly got 'new' ducal titles or with a more limited royal history (probably taking into account that Leonore was the spare at that point).
And while Estelle did get a ducal title with a lot of history; her younger brother's title has only been awarded to future kings.
Estelle: Östergötland
Sune Sik, Duke of Östergötland 12th century (according to 18th-century Swedish historian Magnus Boræn)
Prince Magnus, Duke of Östergötland 1560–1595
Prince John, Duke of Östergötland 1606–1618
Princess Maria Elizabeth, Duchess of Östergötland 1612–1618 as consort and widow of Prince John
Prince Fredrik Adolph, Duke of Östergötland 1772–1803
Prince Oscar, Duke of Östergötland 1829–1872, then
King Oscar II of Sweden and Norway
Princess Sophia, Duchess of Östergötland 1857–1872 as consort of Prince Oscar, then Queen of Sweden and Norway
Prince Carl, Duke of Östergötland 1911–1937, Queen Astrid of Belgium's brother, later Prince Bernadotte
Princess Estelle, Duchess of Östergötland 2012–
Oscar: Skane
Prince Carl, Duke of Scania (1826-1859), later
King Carl XV of Sweden and Norway
Prince Gustaf Adolf, Duke of Scania (1882-1950), later
King Gustaf VI Adolf of Sweden
Prince Oscar, Duke of Skåne (2016–present)
Alexander: Söndermanland
Erik Magnusson, son of King Magnus III, from 1302 until his death in 1318
Prince Karl, son of King Gustav I, from 1560 until he became King in 1604
Prince Karl Filip, son of King Karl IX, from 1609 until his death in 1622
Prince Karl, son of King Adolf Fredrik, from 1772 until
he became King in 1809
Prince Oscar, son of King Karl XIV Johan, from before 1818 until
he became King in 1844
Prince Carl Oscar, son of Crown Prince (later King) Karl (XV), from his birth in 1852 until his death in 1854
Prince Wilhelm, son of King Gustaf V, from his birth in 1884 until his death in 1965
Prince Alexander, grandson of King Carl XVI Gustaf, from 2016
Gabriel: Dalarna
Prince August, Duke of Dalarna 1831–1873
Prince Carl Johan, Duke of Dalarna 1916–1946
Prince Gabriel, Duke of Dalarna 2017–present
Leonore: Gotland
Duke Eric, Lord of Gotland (1397)
Ex-King Eric, Lord of Gotland (1439–1449)
Prince Oscar, Duke of Gotland (1859–1888)
Princess Leonore, Duchess of Gotland (2014–present)
Nicolas: Angermanland
Prince Nicolas, Duke of Ångermanland (2015 - present)
Adrienne: Blekinge
Princess Adrienne, Duchess of Blekinge (2018 - present)