Prince Louis hits a very important royal baby milestone: the wave

Princess Charlotte of Cambridge is the reigning queen of the cute royal wave, but it sounds like she's about to have some competition from her baby brother.

During her visit to military personnel and families serving in Cyprus, the Duchess of Cambridge chatted to a fellow mum about her son Prince Louis, now nine months old.

The royal mum mentioned her youngest child had hit a new milestone.

"She asked whether [my daughter] was sleeping through the night, and she told me that Louis is starting to wave," Rhian Davis tells People of the conversation.

LISTEN: Episode 2 of 9Honey's royal podcast The Windsors looks at Duchess Meghan's life pre-Prince Harry. (Post continues.)

Of course, a baby learning to wave is always adorable.

However, the skill is perhaps even more crucial for royal kids, who spend much of their childhoods waving to members of the public and media.

At ages five and three respectively, Prince Louis' older siblings have already put their personal stamp on the traditional royal wave.

Although he'll one day be King of England, Prince George tends to be a rather, dare we say, reluctant waver.

However, there have been some memorable instances of the little prince spicing up his wave.

Take, for instance, this adorable two-handed effort during the Royal Tour of Canada in 2016:

Princess Charlotte, on the other hand, delivers ALL the sass when greeting the public.

The princess has been an enthusiastic waver since day dot and seizes any opportunity to unleash her wave on the public.

Here she is at Princess Eugenie's wedding in October, calmly and confidently showing the other members of the bridal party how it's done:

At nine months of age, Prince Louis is still busily mastering the basics, but his own personal waving style will surely emerge in the near future—perhaps we'll finally catch a glimpse of it at Trooping the Colour next year.

Until that moment arrives, we can all enjoy these photos of Princess Charlotte's wave and its adorable evolution: