Kate and William got married at Westminster Abbey on April 29, 2011 with millions of people all round the world watching from their homes while others flooded the streets to show their support.
Sources say the couple are marking today privately in a low key way at their London home while preparing for the new baby, however this plan could easily if Kate goes into labour and has to be admitted into the hospital.
According to itv report, today is now the favourite date for the arrival of their new son or daughter, with bookmaker William Hill giving odds of 7/2.
The royal union is blessed with a young boy, Prince George.
We celebrate with the royal couple on their wedding anniversary and wish them a safe delivery.