GLASTONBURY ABBEY (pictured here) is the site of the first Christian Church (above ground) in the world. Originally built by Joseph of Arimathea. The original size was probably the same as the Tabernacle in the Wilderness.

Eusebius (A.D. 260-340), Bishop of Caesarea and the Father of Church History says: "The Apostles passed beyond the Ocean to, the Isles called the Britannic Isles."  Dem. Evangal., 3.7

History
Joseph of Arimathea was the Virgin Mary's Uncle (younger brother of her father according to the Talmud). He lived in the town of Arimathea, called Arimathaim in the Septuagint and Amartha by the Historian Josephus. This is present Day Ramallah which is eight miles North of Jerusalem. He was a wealthy merchant having a fleet of ships that delivered Tin from the mines in Cornwall, England to Phoenicia. Because of the Tin trade he was well acquainted with the British kings Beli, Lud, Llyr and Arviragus, who gave Joseph and his companions twelve 160 acre parcels of land, tax free. Arviragus would become God's "Protectorate" for Glastonbury. Caradoc, Pendragon of England, would become God's "Protectorate" of the fledgling English Church. Caradoc spent seven years "house arrest" before returning to Britain. It was his children who were the core of the Roman church.

Joseph, with many disciples traveled from the holy land by Phoenician boat and landed at Marseilles (a Phoenician trading post), in the Vienoise province of the Gauls (France) in the year 35 AD. From there Joseph went on to England, to establish seminaries and send out missionaries. Cardinal Baronius, Curator of the Vatican library, in his "Ecclesiastical Annals", gives this account. "In that year the party mentioned was exposed to the sea in a vessel without sails or oars. The vessel drifted finally to Marseilles and they were saved. From Marseilles Joseph and his company passed into Britain and after preaching the Gospel there died."

Here's Cardinal Baronius' complete list of passengers:

St. Mary, wife of Cleopas St. Eutropius St. Salome St. Martial St. Trophimus

St. Cleon St. Saturninus St. Maximin (the blind man) St. Sidonius (Restitutus) St. Joseph of Arimathea

St. Mary Magdalene St. Martha St. Lazarus Marcella, the Bethany sisters' maid

Other records state that James and Mary, the mother of Jesus, were also in the boat. 
Philip was waiting for the travelers in France. There is testimony asserting his commission in Gaul, all of which say that he was received and consecrated Joseph as the Apostle to Britain, prior to his journey there. 

Formation of the church in England
St Paul appointed Aristobulus (Rom. 16:10) one of the 70 disciples, father-in-law of St Peter, as first Bishop of Britain. He also made Linus first Bishop of Rome; Linus was the son of Caractacus (also called Caradoc), the British King, who was taken prisoner to Rome.
Claudius, Emperor of Rome, gives his daughter in marriage to the British king Caractacus, and adopts his daughter Gladys, in an effort to end the war with Britain. Upon adoption Gladys' name is changed to Claudia. Caractacus is then betrayed and taken prisoner in Rome. He gives a speech before the Roman senate that is so moving they decide not to put him to death, but to keep him prisoner in the British embassy in Rome. And this house prison becomes the vehicle that allows Paul to preach, even though illegal, under "house arrest" in the British embassy for two years.

When St Paul went to Rome as a prisoner he found Linus and Claudia there, British Christians converted by Joseph of Arimathea. Hence the British Church is older than the Church in Rome. It is interesting to observe that Pudens, Linus and Claudia are mentioned by St Paul in 2 Timothy 4:21, which Epistle the Apostle wrote when he was himself a prisoner in Rome and a friend of these British Christians. Tradition has it that St Paul himself came to Britain. St. Paul's Cathedral, in London, now stands on the very spot where Paul preached to the masses. Others that have witnessed in Britain were St Barnabas, Simon Zelotes. Aristobulus is said to have died at Glastonbury. Joseph of Arimathea died at Glastonbury on July 27th, A.D. 82, and on his tombstone was written, in Latin, "After I had buried the Christ, I came to the Isles of the West; I taught; I entered into my rest." - Cressy, the Benedictine Monk and historian.

Perhaps the most wonderful tradition of all is that our Lord actually came as a boy, accompanying Joseph of Arimathea on one of his expeditions to seek metal, he being a rich merchant in metals, the tin and copper mines in Cornwall then being the richest in the world.

Converts literally flooded into Glastonbury for conversion, baptism, instruction and missionary assignment. Philip sent, from Gaul alone, one hundred sixty disciples to assist Joseph and his team with the crowds. One of the first to go out from Glastonbury was Mary and Martha's brother Lazarus. He headed straight back to Marseilles where he held the Bishopric for seven years. Mary and Martha both lived out their lives, preaching and teaching in the south of France. Glastonbury then becomes the base for the Christian outreach. The Gaulic records state that for centuries the Archbishops of Treves and Rheims were all Britons supplied by the mother church at Glastonbury-Avalon. St. Cadval, a famed British missionary, going out from Glastonbury, founded the church of Tarentum, Italy, A.D. 170 four hundred years before the time of St. Augustine and at least fourteen years after King Lucius Christianized all of Britain in A.D. 156!

• Historians William of Malmesbury, Maelgwyn of Llandaff and Polydore Vergil all place Joseph of Arimathea at Glastonbury. Four Church councils ( Pisa 1409, Constance 1417, Sienna 1424 and Basle 1434), mention that "the Churches of France and Spain must yield in points of antiquity and precedence to that of Britain as the latter Church was founded by Joseph of Arimathea immediately after the passion of Christ."
• In St. Jerome's translation, Joseph's official title is given as 'Nobilis Decurio', a minister of mines for the Roman empire, with direct access to Pilate himself. 
• Gildas, the British historian (A.D. 516-570) says: "Meanwhile, these islands received the beams of light - that is, the Holy precepts of Christ, the true Sun - at the latter part, as we know, of the reign of Tiberius Caesar." 'As we know' seems to refer to a generally accepted knowledge. This date would be at the latest A.D. 37, some four years after the Crucifixion. 
• The Venerable Bede, writing about AD 740, says: "The Britons preserved the Faith which they had received under King Lucius uncorrupted, and continued in peace and tranquility until the time of the Emperor Diocletian."
• The observance by the Greek Church of the martyrdom in Britain of Our Lord's disciple, St. Simon Zelotes, on May 10, AD 44 (a date supported by Cardinal Baronius; and with Hippolytus' (born about AD 160) inclusion of that Apostle in his lists as "Bishop of the Britons". All these are testimony to the year AD 37 as marking the coming of the first Mission.

Many famous names are recorded as having been associated with Glastonbury-Avalon:

• Sidonis, Saturninus, and Cleon taught and supported other missionaries in Gaul, then returned to Britain.
• Martial's parents, Marcellus and Elizabeth were there along with St Zacchaeus.
• Parmena, disciple of Joseph, was appointed the first Bishop of Avignon.
• Drennalus, helped Joseph found the church at Morlaix. He was then appointed to Treguier as it's first Bishop.
• Beatus founded the church in Helvetia, after receiving his baptism and education at Avalon.
• Beatus was baptized by St. Barnabas, the brother of Aristobulus, sent in advance by St. Paul to Britain. He is referred to in scripture as Joses, the Levite.
• Mansuetus was consecrated the first Bishop of the Lotharingians A.D. 49, with his See at Toul. He also founded the church at Lorraine.

Historical note:
Mansuetus was a constant visitor to Rome after Claudia had married Pudens. He was a friend of Linus, the Bishop of Rome, and brother of Claudia. After the death of St. Clement, Mansuetus became the third official Bishop of the British Church at Rome. Thus we have three disciples of Avalon, instructed by St. Joseph, to become, in succession, Bishops of Rome.

References: 

1. The Coming of The Saints, by Taylor 
2. St. Joseph of Arimathea at Glastonbury, by Lewis, from Artisan Sales
3. The Origin and Early History of Christianity in Britain, by Andrew Gray; from Artisan Sales
4. Did the Apostle Paul Visit Britain?, by R.W. Morgan, from Dolores Press
5. Did Our Lord Visit Britain, by Rev. C. C. Dobson; from Covenant People
6. The Drama of the Lost Disciples, by George F. Jowett,; from Artisan Sales