Numbering just over 100 men, the Vatican’s Swiss Guard are members of the oldest standing army in the world and are probably the smallest one. Although they now have a largely ceremonial role, the Swiss Guards are part of an elite force that is ready at any moment to sacrifice their lives for the pope, as 147 of them did during the sack of Rome in 1527. This weekend sees the anniversary of that sacrifice by the Guards which is marked by the annual swearing-in ceremony for the new recruits. Listen to the following report by Susy Hodges that explores one of the Vatican's most colourful institutions. ...