The 26 new papal Swiss Guards who were sworn in on 6 May took their oath of allegiance to the pope in the Paul VI audience hall because of the heavy rain. Usually the colourful ceremony takes place in the open.

There are between 200 and 250 guards at the service of the pope although recruiting guards has been increasingly difficult in recent years.

The annual event commemorates 6 May 1527, when 147 Swiss Guards died protecting Pope Clement VII from the army of the Holy Roman Emperor. The pope fled via the 800-m Passetto di Borgo tunnel to the nearby refuge of Castel S. Angelo.

The Swiss Guards must be of Swiss nationality, as well as being Catholic, single and under the age of 30. In addition to protecting the pope, the guards perform ceremonial duties and assist at Vatican functions, and they serve for a minimum of two years.

The much-photographed soldiers are famous for their blue, gold and red uniforms, and ancient halberd weapons. The Swiss Guard is the oldest army in the world and celebrated its 500th anniversary in 2006.

The Swiss Guards became the centre of a scandal in 1998 when their commander Alois Estermann and his wife were assassinated in their home on Vatican territory on 4 May by a young guard, Cedric Tornay, who is then alleged to have committed suicide on the spot. The exact details of the deaths have never been clarified to the satisfaction of Tornay