Prince Harry Shares Never-Seen-Before Photo of Archie to Celebrate Dad Charles' 71st Birthday

In a tribute to Prince Charles on his on 71st birthday, Prince Harry shares a never before seen picture of his son, Archie. In his message he also reveals his father's nicknames.

In honor of Prince Charles for his 71st birthday, members of the royal family have been sharing pictures of some of their favorite moments with the future king. Sussex Royal captions their picture saying:

"Happy birthday to His Royal Highness The Prince of Wales - Sir, Pa, Grandpa! ?."

The black and white picture of Harry and Charles shows them standing side by side as they look down lovingly at Archie. It was taken at his christening, in July.

In his caption for Charles, who is a grandfather of four, Harry makes his nicknames known and tenderly refers to him as "Pa, Grandpa."

The latest image from the christening has never been seen before because Harry and Meghan Markle made the decision to brake royal tradition and not allow any press into the event.

Continuing to maintain their family's privacy since then, the couple have only made a few pictures of the christening public.

Keeping the birthday messages rolling, Prince William and Kate Middleton also shared an adorable photo of Charles with his other grandson, Prince Louis The couple says:

"Wishing a very happy Birthday to The Prince of Wales!"

For his 71st birthday, he is currently on a solo two-day tour of India. He is visiting the country in support of efforts to address climate change and to see first hands the steps they are taking to address their smog issues.

Charles, was pictured riding an electric rickshaw and he also visited a Sikh temple in the country to learn more about its culture.