The Lateran Treaty between the Italian State and the Holy See on 11 February 1929 coincided with the tenure of the guard commander Hirschbühl. In it, the Holy See had been granted the exclusive and absolute right to manage all its political and legal affairs on its own. The Swiss Federal Council confirmed the parliament's opinion on 15 February: "The papal guard cannot be regarded as foreign, armed unit in accordance with Article 94 of the military criminal law, because this force is a simple security police, and anyone can, as before, come into their service, without the consent of the entire Federal Council."
The creation of the new state, the Vatican City, required on its border the introduction of regular checkpoints at the Arco delle Campane (bell gate) and the Porta Sant'Anna (Annator). The Portone Borgia, however, was closed. In 1929, work began on the construction of new office and living quarters for officers and NCOs. It remains to be said that, besides the already mentioned works, the restoration of the little church consecrated to St. Martin and St. Sebastian, which is situated in the Swiss quarters, was also restored. Pope Pius V had built this church in 1568 specifically for the Guard, which now was once again at the disposal of the Guard. The church of San Pellegrino with its century-long history of the Swiss with the Holy See, on the other hand, was made available to the Vatican’s Vigilanza.