Now this is fascinating, and starkly reveals your frame of mind.
First, I have never suggested the Catholic Church began in the 11th century. The Catholic Church began as a true church in Rome, but it's leaders, when put under pressure from pagan persecution, compromised first by abandoning the Sabbath in favor of the Roman day of the sun, Sunday, and at the same time when Constantine shifted his power base from Rome to Istanbul, this left a vacuum wherein there was needed a civil authority to fill. Sadly, the bishops of time took this upon themselves, and began to enjoy the baubles of office and things went downhill from there on.
The next point need some clarification. Yes, Ireland was converted around the 4th century. But she wasn't the first. There were Gallic communities from Ireland to Asia minor from the 3rd century before Christ. There was a trade route between Asia what Ireland, that led from Asia across northern Italy, southern France, and thence to Ireland and Scotland and Wales. Galatia was Gallic. When in the first century the gospel through Paul and others converted many pagans in that area, in the towns of Ephesus, Thessalonica, Thyatira etc, those converts then shared the good news as they traded and traveled, and they gospel itself reached the shores of Britain much earlier than you would imagine. Patrick's Father was already a Christian minister in his native Scotland, and presided over a church there. Patrick, after being covered himself as a slave, was merely carrying on the practise of preaching and teaching the goods news, and without any input, support, or miraculous nonsense fables about his flying to Rome and removing snakes. Patrick wasn't Catholic. It took several centuries before the church in Rome even acknowledged he ever existed, because the gospel he preached was so different, and the churches and schools he established, so significantly opposed to Rome's growing mix of pagan profane with the holy, and it wasn't until the Celtic church had grown so powerful across both islands that time finally had to admit to Patrick's ministry, and claiming him as their own by the embellishment of fantastic stories and miracles. All lies.
Oh, and there was also a vast difference between how Patrick established the church in Britain, with peaceful means through preaching and serving the communities, raising up ministers from the evangelical schools he established, to the methods used by Clovis on the continent a couple hundred years later. Rome didn't have a gospel to peach. They had coercion and force of arms to convince the people to submit the Pope's authority and rule.
Patrick led the people to Christ. They have up their pagan practises of witchcraft and superstitions, and embraced the cross of Calvary, becoming humble servants of Christ. You on this forum do not peach Christ. You preach submission to papal authority just as Augustine did so many centuries ago. And just as Augustine was rebuked by the Celtic church in Wales and sent packing, do also do I rebuke you. Peach Christ and Him crucified and I'll listen. But you Popes and your rituals and your long tedious prayers and traditions, and your Sunday, don't interest me.
What will you do now? Do as Augustine did and arrange a marriage with a pagan British king and a Catholic princess, who then raised an army against the church in Wales murdering over 3000 students at a school there? I have seen your statements previously espousing the killing of heretics and overpowering opposition by force of arms, even just the past above you continue this train of thought, which is typically Catholic. Will you do thus to those on this forum who reject you?
Any church that takes one small step in the direction of Rome, is taking a leap in the direction of apostasy.