It is proper that a history of Christianity in Nigeria should begin with the Itsekiri and their  neighbours. Because of their geographical location the Itsekiri came into contact with Portuguese priest who accompanied Portuguese explorers in their bid to find a sea route to India in the fifteenth century. By about 1477 the first European contacts were made with Benin, and by 1555 Augustinian monks visited Warri. They were sent by Gasper, who was the bishop of the diocese of Sao Tome. One of the monks, Father Franscisco a Mater Dei, baptized the son of the Olu  of  Warri  under the name of Sebastian.[1]
 
 

When Sebastian later succeeded his father he encouraged the work of the Portuguese missionaries, and indeed allowed his son, Domingos, to be sent to Portugal and trained for the priesthood.It was hoped that if this happened the spread of Christianity to the hinterland would be expedited since indigenous priests would not suffer from the ill effect of the equatorial climate which imposed a serious limitation on the work of the European missionaries. However, Domingos  was not able to qualify for the priesthood since he ended his ten years stay in Portugal by marrying, contrary to the stipulation of the Roman Catholic Church in respect of those who wish to enter the priesthood. (His wife was a Portuguese woman.) Some other attempts made later to train indigenous priest also failed, with the result that the  Itsekiri  came to the conclusion that the Almighty did not intend Africans to become  celebate  priests![2]
 
 

 The difficulty of providing trained indigenous priests constituted a set back to the propagation of Christianity among the  Itsekiri . As already indicated, the climate of the area was  unfavourable  to European missionaries; the place was not only too humid, it was also infested by mosquitoes, the carriers of malaria which was to be a formidable menace to missionary work in this area until after 1854.  Furthermore, the Portuguese kingdom, experiencing a period of decline as a result, among other things, of her loss of naval power, was incapable of supporting Portuguese priests who worked among the  Itsekiri  for a long time.
 

All this apart, had the  Itsekiri  themselves responded  favourably  to the appeal of the Portuguese missionaries, Christianity might have taken deep root, and possibly spread to the hinterland. But they did not. So superstitious were they of the implication of baptism that they were most reluctant to release their children for baptism, fearing, as they did, that the children would die shortly after baptism.  Thus, the adverse climate, the decline of Portuguese empire consequent upon the poverty of that kingdom and her loss of naval power, the unsuccessful attempts to train indigenous priests, and the superstition of the  Itsekiri , all militated against the work of the Portuguese missionaries in Ode  Itsekiri, the capital of the  Itsekiri  kingdom.
 

But these were not the only adverse factors.  Perhaps even more important was the slave trade.  The Portuguese priests who came to the area from the sixteenth century onwards did so in the gunboats of slave traders.  It is even reported that some of them, in a desperate effort to maintain themselves in the area, participated in the inhuman trade.  Even if it be admitted that on the whole the Roman Catholic Church at the time did not approve of the slave trade, yet she took no positive steps to discourage the inhuman traffic in living tools.  Instead, there was an attempt to see the good side of the inhuman trade: the possibility of converting the negro slaves once they were transported from the darkness of  Africa to the marvelous light of Christianity which the Church in Europe believed to be in her possession to radiate. As a matter of fact, most of the slaves carried from the West Coast did not land in Europe; they were carried to sugar plantations in Americ where they were treated as beasts of burden.
 

No matter in what bright  colours  the slave trade may be painted, viewed in retrospect and from the West African stand point, on no ground can it be justified.  Any Christianity, therefore, which allied itself to such a diabolic force s the Portuguese slave trade was doomed to fail.  Thus the failure of the first attempt to plant Christianity among the  Itsekiri , and in part of what was later to be known as Nigeria, was, more than any other factor, due to the slave trade.  Before the end of the eighteenth and the beginning of the nineteenth centuries, Roman Catholicism had practically disappeared from Ode  Isekiri.
 

 However, as stated elsewhere[3], in spite of the difficulties which rendered missionary work in the area of little consequence some impression was made as is evidenced from the court of the Olu of Warri  even today.Even among the Urhobo in the hinterland some impression was made, especially by Father Monteleone, a prefect from Sao Tome, who, according to Professor Ryder[4], came in contact with the Urhobo in 1689 in his unsuccessful attempt to visit Benin from  Warri.