Whether or not James the Greater traveled to Spain is highly contested.
The entry on St. James the Greater in the Catholic Encyclopedia from newadvent.org lists some reasons why this is contested.
With regard to the preaching of the Gospel in Spain by St. James the
greater, several difficulties have been raised:
- St. James suffered martyrdom A.D. 44 (Acts 12:2), and, according to
the tradition of the early Church, he had not yet left Jerusalem at
this time (cf. Clement of Alexandria, Stromata VI; Apollonius, quoted
by Eusebius, Church History VI.18).
- St. Paul in his Epistle to the Romans (A.D. 58) expressed the
intention to visit Spain (Romans 15:24) just after he had mentioned
(15:20) that he did not "build upon another man's foundation."
- The argument ex silentio: although the tradition that James founded
an Apostolic see in Spain was current in the year 700, no certain
mention of such tradition is to be found in the genuine writings of
early writers nor in the early councils; the first certain mention we
find in the ninth century, in Notker, a monk of St. Gall (Martyrol.,
25 July), Walafried Strabo (Poema de XII Apost.), and others.
- The tradition was not unanimously admitted afterwards, while
numerous scholars reject it. The Bollandists however defended it
(see Acta Sanctorum, July, VI and VII, where other sources are
The fact that James the Greater was martyred in Jerusalem is pretty widely accepted since it is mentioned in the Bible.
Acts 12:1-2 NIV
1 It was about this time that King Herod arrested some who belonged to
the church, intending to persecute them. 2 He had James, the brother
of John, put to death with the sword.