KING Charles III has been filmed forgetting the date and raging against a faulty pen during a signing ceremony in Northern Ireland.

The new monarch was visiting the country to attend a memorial service in honour of his late mother Queen Elizabeth.

However, when signing a visitors book in-front of cameras at Hillsborough Castle – the royal residence near Belfast – Charles reacted with frustration when a pen leaked onto his hand.

“Oh god I hate this!” said the King as he handed the pen to his wife Camilla, the Queen Consort.

“Oh look, it’s going everywhere,” she said, watching as her husband wiped ink from his finger.

“I can’t bear this bloody thing!” said Charles. “Every stinking time.”

It comes just days after footage showed the new King gesture in irritation at the presence of an ornate pen holder on the table during his first Privy Council meeting.