The Duke and Duchess of Cambridge have announced the name of their third child. Kensington palace tweeted Friday morning: "The Duke and Duchess of Cambridge are delighted to announce that they have named their son Louis Arthur Charles. The baby will be known as His Royal Highness Prince Louis of Cambridge."Prince Louis is fifth in line to the British throne, after grandfather Prince Charles, father Prince William and his two older siblings.The newest arrival to the royal family was born on Monday and weighed eight pounds and seven ounces.He is a younger brother to Prince George, 4, and Princess Charlotte, 2, and is Queen Elizabeth II's sixth great-grandchild.His birth was also a significant moment for Charlotte, the first princess who will not be overtaken in the line of succession by her younger brother.Before the 2013 Succession to the Crown Act, the newborn prince would have jumped above his older sister in the line for the throne.But the act means that a female's claim to the royal throne can no longer be diminished by a younger brother.