During the latter part of the 17th and the early part of the 18th Centuries, when the Catholic clergy had prices on their heads, the most reviled profession in the city was that of priest-catcher. It was a lucrative business that offered £150 for the capture of an archbishop or bishop and £50 for the taking and conviction of a priest.

To the citizens of Dublin -- Catholic and Protestant -- the priest-catcher was the lowest form of life. Once a priest-catcher had been identified, he could never again walk the streets without grave risk to his life. In 1728, the Protestant Archbishop of Dublin told the Archbishop of Canterbury that it was not uncommon to see mobs of 500 or 600 angry Dubliners armed with cudgels and stones in hot pursuit of a priest-catcher.

The most infamous priest- catcher of those times was a Spaniard called John Garxia.

Garxia arrived in Dublin in 1717 and he immediately set about infiltrating the Catholic community here. He posed as a priest and stayed at the Franciscan friary of Adam and Eve on Merchants Quay. The present day Adam and Eve church takes its name from the Adam and Eve tavern on Cook Street where the Franciscans once held secret masses. Catholics posing as drinkers would be admitted by a guard on giving the password: "I am going to the Adam and Eve."

A few months later, Garxia made his move. He went to Dublin Castle and handed over information relating to the activities of various priests. Acting on this information, the authorities raided several houses around the city on the morning of June 1st, 1718 and rounded up seven clergymen. The haul included Doctor Edmund Byrne the Archbishop of Dublin, and Fr Anthony Bryan, who had earlier been parish priest of Rathfarnham.

The bishop and priests were put on trial in November of that year with Garxia as the star witness. With the exception of the archbishop, the priests were found guilty and sentenced to transportation. It is not known whether this sentence was carried out or not. England went to war with Spain at Christmas that year and the ships that were used for transportation were requisitioned by the authorities. It is known, however, that priests who had been transported earlier that year returned under false names and were generally left to go about their work unharmed.

Meanwhile, Garxia was being subjected to the usual treatment reserved for priest-catchers by the citizens of Dublin. In a letter to the Lord Justice, he complained that the mob had "contrived ways to take away his life". He mentions one incident in particular in James' Street when he was "insulted, beat and much abused", barely escaping with his life.

Garxia was the last of the official priest-catchers. With the increasing toleration of Catholics by the authorities and constant harassment by the inhabitants of Dublin, Garxia realised that his days were numbered and he left Ireland in 1723.