The Swiss Guard is a small force responsible for the security of the Apostolic Palace, the entrances to the Vatican City and the safety of the Pope.

The force is specifically limited to a hundred soldiers only. Although they are fully trained and equipped in modern weaponry and tactics, they also receive instructions in using the sword and halberd. The force is recruited from Roman Catholic males of Swiss nationality; after they have completed basic training with the Swiss military they can obtain certificates of good conduct and apply to serve. Recruits must be between 19 and 30 and at least 174 cm (5ft 9in) tall. If accepted, new guards are sworn in every May 6 in the San Damaso Courtyard in the Vatican. The term of service is between two and 25 years. Their official dress uniform was altered in 1915. It is a jumpsuit which has a distinctly Renaissance appearance. It is colored in blue, red, orange, and yellow. A popular misconception is that these dress uniforms were designed by Michelangelo, but in fact this is untrue. Their routine garb is more functional, consisting of blue coveralls with a black beret. When his name is called, each new Guard approaches the Swiss Guard's flag, grasping the banner in his left hand. He raises his right hand with his thumb, index, and middle finger extended, a gesture that symbolizes the Holy Trinity. The chaplain of the guard reads aloud the oath in German, the guard's official language:

I swear to serve faithfully, loyally, and honorably the person of the Sovereign Pontiff, his Holiness Pope John Paul II (or the name of the reigning pope), and his legitimate successors canonically elected, as well as, to dedicate myself to them with all my strength by sacrificing, should it become necessary, even my own life in their defense. I likewise assume this promise toward the members of the Sacred College during the period of the Sede Vacante. Furthermore, I pledge to the Commandant and to my superiors, respect, obedience, and fidelity. By this I swear. May the Almighty and His Saints protect me.

The Swiss Guard is not considered to belong to any larger force, but is instead the army of the sovereign state of the Vatican. It is currently composed of 4 officers, 23 NCOs, 70 halbardiers, 2 drummers, and a chaplain.

The Guard was founded by Pope Julius II in 1505 to provide a constant core of soldiers to protect the Pope; the Swiss mercenaries were an obvious choice. The official founding date is given as January 21. The force has varied greatly in size and has even been disbanded. The soldiers' most significant action was on May 6, 1527 when 147 of them died fighting the forces of Charles V. Since 1859 they have been the only mercenary group permitted under Swiss law.

Estermann killing

On May 6, 1998, Swiss Guard Cedrich Tornay killed Colonel Alois Estermann, commander of the Swiss Guard, and his Venezuelan wife Gladys Meza Romero, and afterwards, himself, in the commander's home.

Just ten hours before the killings, Pope John Paul II had appointed Estermann as the 31st "captain commander". "It's an honor," Estermann had told the Swiss newspaper Le Matin. "These are big responsibilities. But behind this choice, I see the will of God, who will help me accomplish my service well."

Estermann had joined the Swiss Guard in 1980. On May 13, 1981, after the Pope had been shot by Mehmet Ali Agca, Estermann jumped onto the moving Popemobile and shielded him with his own body.

Tornay's motive was probably being upset about a reprimand from Estermann for not having returned to barracks on time, and not being one of the guardsmen who were to be honored by the pope in a ceremony.

As a result of the murder, some changes have taken place within the Swiss Guard, for instance new methods of candidate screening, a reform of the training and promotion procedures and new recruiting campaigns. Pius Segmuller was appointed the new commander.