Sort:  
  1. Denmark 🇩🇰: in use since 1625
  2. Netherlands 🇳🇱: adopted in 1660
  3. Nepal 🇳🇵: introduced in 1743
  4. United Kingdom 🇬🇧: in place since 1801
  5. Chile 🇨🇱: started in 1817
  6. Argentina 🇦🇷: adopted in 1818
  1. Peru 🇵🇪: in use since 1825
  2. Uruguay 🇺🇾: began in 1828
  3. France 🇫🇷: in place since 1830
  4. Belgium 🇧🇪: started in 1831

The note clarifies that flags from the same year are listed for convenience.