Boos from anti-monarchy protesters could be heard over the hundreds of cheering well-wishers who greeted the King and Queen Consort at Cardiff Castle.
Around 40 demonstrators gathered outside the castle walls on Friday with banners displaying messages such as “Abolish the Monarchy” and “Democracy Now”.
It is the first negativity the King has encountered during his tour of the devolved nations as the new monarch.
Some protesters held giant Owain Glyndwr flags as the visit fell on the day that celebrates the legacy of the rebel who is considered to be the last native-WelshPrince of Wales.
Many wore T-shirts bearing the words “Yes Cymru” – the slogan of independence campaigners.