Every year on the Anniversary of the 1527 Sack of Rome, the new recruits for the Pontifical Swiss Guard swear an oath to protect and defend the Pope, with their lives if necessary. This year 23 young men joined their peers and predecessors in making that oath.

"You are witnesses of Christ – here in Rome, in your homeland of Switzerland and wherever you go," Cardinal Pietro Parolin, Vatican Secretary of State, told the new guards May 6.

Each year before their official swearing-in Cardinal Parolin celebrates an early-morning Mass for the new guards in St. Peter's Basilica.

He told the guards that in a world that desperately wants light but "often doesn't have the courage to welcome it," their commitment is an example for their peers, "who are hungry for meaning and fullness."

Cardinal Parolin told to the guards that "you can tell them it's worth it to propose large and beautiful things, while behaving with commitment and dedication," but stressed that this is always accompanied "by some fatigue."

He pointed to the May 6, 1527 battle that has come to be known as the Sack of Rome, and which was the most significant and deadly event in the history of the Swiss Guard.

In the course of the battle, 147 guards lost their lives while fighting the army of the Holy Roman Empire in defense of Clement VII, who was able to escape through a secret passageway leading from the Vatican to Castel Sant'Angelo, which sits next to the Tiber River.

Cardinal Parolin stressed that being faithful isn't always easy, just as it wasn't for the guards who lost their lives in the battle. However, he referred to them as heroes, and examples to follow without delay.

"Dear guards, do not wait. Begin already today to bear witness – with your fidelity in the daily service of the Holy Father, with your brotherhood, and with the good relationships among you," he said.

By becoming an example in the faith, the guards can bear witness to the fact that "the Lord is alive, has compassion and is merciful, that he draws near to men, that he wants to give peace, joy and true fullness to heal every wound," the cardinal continued.

He urged them to always recognize and love God for his constant presence in their lives, and encouraged them to follow the example of their patron saints – St. Martin, St. Sebastian and St. Nicholas of Flue – at the moment of taking their oath.

Cardinal Parolin prayed that the saints would always assist the guards in fulfilling the promise they make, adding that "their hearts were filled with the joy of the Lord, which no one can take away."

With a motto of "Courage and Loyalty," the Pontifical Swiss Guard has just over 120 members, making it the smallest, though oldest army in the world.

The official swearing in ceremony took place in the San Damasco courtyard of the apostolic palace.

During the ceremony, each new recruit approaches the flag of the Swiss Guard when his name is called out. Firmly grasping the banner with his left hand, the new guard raises his right hand and opens three fingers as a sign of his faith in the Holy Trinity.

As he holds up his fingers, the guard proclaims this oath: "I, N, swear diligently and faithfully to abide by all that has just been read out to me, so grand me God and so help me his saints."

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In English, the full oath reads: "I swear I will faithfully, loyally and honorably serve the Supreme Pontiff Francis and his legitimate successors, and also dedicate myself to them with all my strength, sacrificing if necessary also my life to defend them. I assume this same commitment with regard to the Sacred College of Cardinals whenever the see is vacant. Furthermore I promise to the Commanding Captain and my other superiors respect, fidelity and obedience. This I swear! May God and our Holy Patrons assist me!"