I think you could go to any good encyclopedia, including probaby the Wikipedia, and get complete information about this, whereas I (and I imagine others here who may have made some study of it) can only point out certain things to, I hope, sustain your interest in a fascinating topic.
England was in fact Christianized in the first millenium by an emissary from Rome who became the first Archbishop of Canterbury. His name was Augustine, but he is not to be confused with St. Augustine, Bishop of Hippo. He is, however, considered a saint (St. Augustine of Canterbury, in fact). A number of other archbishops of Canterbury are saints, most notably St. Thomas a Becket, a multi-volume story in his own right.
Everything was going swimmingly. In fact, England was considered by many the most Catholic country in Europe. Then along come this guy called Henry VIII and he decrees a separation from the Church of Rome and replaces the Archbishop of Canterbury (I think his name was Warham) with his own pick, one Thomas Cranmer, who had Lutheranizing tendencies. He ended up being the true ruination of the Church in England (a classic case of a fool being capable of as much evil as a knave).
Cranmer was himself a validly ordained bishop, but it was during his ascendency that the validity of Anglican orders was broken by the introduction of defects in intent. He is actually considered an Anglican martyr, because he was executed under the failed attempt of Mary Tudor (herself more than a fool) to restore Catholic Christianity in England.
For centuries thereafter, the Archbishops of Canterbury ruled what they were wont to call the Church of England without official interference from Roman Catholicism. Only in the 19th century were Catholics allowed to function again in England on an equal footing based on freedom of religion. When they finally re-established a hierarchy there, it was found necessary to set up a “parallel” establishment, whereby the Archbishop of Westminster, a prelature cut out of the whole cloth, functions as what the Archbishop of Canterbury should be.
There are far more twists and turns to the story than I have been able to cover, but let me conclude with one extended thought. The “English Reformation” is unique in the establishment of protestantism in that it was based entirely on the ego of one very evil ruler. (One can argue about Luther’s ego, but he was not a ruler and not evil in quite the way Henry VIII was.) England’s defection from Rome was tragic in a unique way. We should be greeting the Archbishop of Canterbury as what he would have been: The primate of England and a if not the precedential prelate of the Roman Church in northwestern Europe.