(Author's Note: The below explanation of inheritance is correct and contradicts what Gardner said above. I agree with what is said below.)

When Jesus became the "David," his brother James became the "Joseph" (and thus, the Joseph of Arimathea). This only changed when Jesus the younger was of an age to inherit the title. After the death of Jesus the Christ, his eldest son Jesus the Justus took over the role of the David, the Davidic king (Author: This is how Jesus also inherited from his own deceased father, meaning that when Jesus was born, he was already king, since his father died while his mother was pregnant�ergo the Nativity story with the Magi hailing him as the King and Savior at his birth).

Jesus' younger son Josephes (the new David's brother) then became the Joseph and Crown Prince (CORRECT), the designated Rama-Theo (Arimathea). But until that time, while his brother Jesus II Justus (called Gais or Gesu in Grail lore) was abroad in Rome and Jerusalem, Josephes' foster-father and legal guardian was his uncle James (the Joseph of Arimathea).

Later, the first-born son of Jesus Justus was Galains (called Alain in the Grail tradition). In accordance with the custom of dynastic wedlock, Jesus Justus would have first married in September AD 73; his wife was a granddaughter of Nicodemus. The legacy of Davidic kingship (which was to become presented as "Lordship of the Grail"), was promised to Galains, and was in time formally passed to him by his uncle and guardian, Josephes. But Galains became a committed celibate and died without issue (LIKE JOHN THE BAPTIST). Hence, the Grail heritage reverted to Josephes' junior line, to be inherited by his son Josue, from whom the Fisher Kings (Priest-Kings) descended.

As we have seen, Joseph of Arimathea had been to Britain with Mary's elder son, the 12-year-old Jesus Justus, in AD 49. This event is well remembered in West Country tradition, and is evidenced in William Blake's famous song "Jerusalem." The stories tell of how young Jesus walked upon the Exmoor coast, and went to the Mendip village of Priddy. Because those royal feet did indeed "walk upon England's mountains green" (albeit the son's feet rather than the father's), a stone in memory of his parents, Jesus and Mary Magdalene, was eventually set into the south wall of St. Mary's Chapel, Glastonbury. This stone, which remains on the site of the original 1st-century wattle chapel, is inscribed "Jesus Maria" and in due course, as one of the most venerated relics of the Abbey, it became a "station of prayer" for pilgrims in the Middle Ages. The original chapel was begun in AD 63 immediately after Mary Magdalene's death, and the old annals all state that Jesus consecrated the chapel "personally, in honor of his mother." It was, therefore, to the Magdalene (not to Jesus the Christ's mother Mary) that the Glastonbury chapel was dedicated by her eldest son, Jesus Justus, in AD 64).