all photos Chris Jackson Pool/Getty Images

Back to work! New dad Prince Harry made his first public appearance after the birth of his and Meghan Markle's son Archie, solo, in The Netherlands, on Thursday. He even wore an Invictus shirt with his new name embroidered on it -- "Daddy." :)

Meghan stayed home with 3-days' old Archie Harrison Mountbatten-Windsor while Harry fulfilled his duties to launch the countdown for the 2020 Invictus Games. At the event, Harry "praised the men and women who had given it all in service to their country, [and will] now do the same on the sports field,” according to royal contributor Omid Scobie. Referencing his and Meghan's commitment to mental health, he said in his speech: "Our mental fitness is key, because without it we fail to operate efficiently. But with it, your physical performance and potential are exponentially improved and we have witnessed this over and over again."

At the event, a young girl gifted Harry with an adorable Invictus onsie for baby Archie, which made the new dad grin from ear-to-ear.