Category: Society / January 9, 2013 9:44 AM EST
The Duchess of Cambridge, Catherine, who is more popularly known as Kate celebrated her 31st birthday on Wednesday (January 9), in what St James' Palace said would be a "private" occasion for the pregnant royal.
The Union flag was erected over Belfast City Hall on Wednesday to mark the Duchess of Cambridge's birthday.
The Duchess of Cambridge has chosen to stay out of the limelight since being treated in hospital for severe morning sickness. She made her first public appearance at the BBC's Sports Personality of the Year Awards in London on Sunday (16 December).
Prince William, the Duke of Cambridge and Kate have been in the spotlight frequently in the past 12 months, and especially since the announcement of her pregnancy.