_.The Duchess of Cambridge is expecting a baby in the summer of 2013. The royal baby will be born third in line and in direct succession to the throne after the Prince of Wales and Duke of Cambridge.
He or she will one day be head of the armed forces, supreme
governor of the Church of England and subsequently head of state of 16
Under the terms of the letters patent laid down by King George V in 1917 only the eldest son of the eldest son of the Prince of Wales is born a prince with the HRH handle.
A son would be born HRH Prince (Christian name) of Cambridge.
If the baby is girl then under the 1917 ruling she will be born Lady (Christian name) Windsor but it is expected that Her Majesty the Queen will make an announcement next year regarding the titles to be borne by the children of the Duke & Duchess of Cambridge. A princess (and future Queen) would be known as HRH Princess _______of Cambridge.