The Queen carried out audiences at Buckingham Palace as police released a man arrested for climbing the gates of her royal residence.
The 93-year-old monarch kept to her diary in the wake of the intruder being arrested at the palace in central London.
A man held after he scaled the front gates was released under investigation as inquiries continue, Scotland Yard said.
Specialist royal police officers arrested a 22-year-old man after he scaled the front gates at around 2am on Wednesday morning.
He was held on suspicion of trespass by specialist royal police officers, the Metropolitan Police said.
The Queen was in residence at the time, a palace spokeswoman said.
She declined to say whether the Queen had been informed of the incident.
The intruder was not carrying any weapons and the incident is not being treated as terror-related, Scotland Yard said.
The Sun reported the intrude was on the loose in the grounds for around four minutes before he was apprehended.
On Thursday morning the Rt Rev and Rt Hon. the Lord Chartres was received by the Queen upon relinquishing his appointment as Dean of Her Majesty’s Chapels Royal.
The Rt Rev and Rt Hon Dame Sarah Mullally also met the sovereign upon assuming her appointment as the new Dean of Her Majesty’s Chapels Royal.
Bishop Sarah, the 133rd Bishop of London, is one of the most senior figures in the Church of England and the first woman to hold the post.
The Queen also carried out a full programme of engagements at the palace on Wednesday, including her regular meeting with Prime Minister Theresa May.