The Union flag was raised at Belfast City Hall on Wednesday (January 9) to mark the Duchess of Cambridge's 31st birthday.
The displaying of the flag comes amid continued protests between unionists and republicans over the use of the flag following a decision by Belfast City Council to limit its use to just 18 days a year.
Since the decision was made in December unionists have protested on an almost nightly basis in east Belfast, leading to 104 arrests and 66 police officers being injured during the protests.
In an attempt to end the unrest a special meeting of unionist representatives in Northern Ireland has been arranged.
Northern Ireland's First Minister Peter Robinson confirmed the that meeting between the various unionist parties will be held at Stormont on Thursday (January 10) to discuss the trouble but those leading the protests have already said they will not take part in the talks.
They have also threatened to take the campaign on to the streets of Dublin on Saturday January 12.