Blessed Pope Pius IX born Giovanni Maria Mastai-Ferretti, was the longest-reigning elected Pope

Pope

The Pope is the Bishop of Rome, a position that makes him the leader of the worldwide Catholic Church . In the Catholic Church, the Pope is regarded as the successor of Saint Peter, the Apostle...

 in the history of the Catholic Church, serving from 16 June 1846 until his death, a period of nearly 32 years. During his pontificate, he convened the First Vatican Council

First Vatican Council

The First Vatican Council was convoked by Pope Pius IX on 29 June 1868, after a period of planning and preparation that began on 6 December 1864. This twentieth ecumenical council of the Roman Catholic Church, held three centuries after the Council of Trent, opened on 8 December 1869 and adjourned...

 in 1869, which decreed papal infallibility

Papal infallibility

Papal infallibility is a dogma of the Catholic Church which states that, by action of the Holy Spirit, the Pope is preserved from even the possibility of error when in his official capacity he solemnly declares or promulgates to the universal Church a dogmatic teaching on faith or morals...

. The Pope defined the dogma

Dogma (Roman Catholic)

In the Roman Catholic Church, a dogma is an article of faith revealed by God, which the magisterium of the Church presents to be believed. The resurrection of Jesus Christ is the basic truth from which salvation and life is derived for Christians. Dogmata regulate the language, how the truth of...

 of the Immaculate Conception

Immaculate Conception

The Immaculate Conception of Mary is a dogma of the Roman Catholic Church, according to which the Virgin Mary was conceived without any stain of original sin. It is one of the four dogmata in Roman Catholic Mariology...

 of the Blessed Virgin Mary

Blessed Virgin Mary (Roman Catholic)

Roman Catholic veneration of the Blessed Virgin Mary is based on Holy Scripture: In the fullness of time, God sent his son, born of a virgin. The mystery of the incarnation of the Son of God through Mary thus signifies her honour as Mother of God...

, meaning that Mary was conceived

Fertilisation

Fertilisation is the fusion of gametes to produce a new organism. In animals, the process involves the fusion of an ovum with a sperm, which eventually leads to the development of an embryo...

 without original sin

Original sin

Original sin is, according to a Christian theological doctrine, humanity's state of sin resulting from the Fall of Man. This condition has been characterized in many ways, ranging from something as insignificant as a slight deficiency, or a tendency toward sin yet without collective guilt, referred...

. Pius IX also granted the Marian title of Our Mother of Perpetual Help

Our Mother of Perpetual Help

Our Lady of Perpetual Help or "Sancta Mater de Perpetuo Succursu" Holy Mother of Perpetual Help is a title given to the Blessed Virgin Mary by Pope Pius IX, associated with a Byzantine icon of the same name dating from the 15th century...

, a famous Byzantine icon from Crete

Crete

Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

 entrusted to the Redemptorist priests.