Of all the 365 islands on Lough Corrib, Inchagoill is the most famous and most visited. The name Inchagoill comes from three Irish words "Inis and Ghaill" meaning the "Island of the Foreigner".

Situated approximately half way between Cong, Co. Mayo and Oughterard, Co. Galway, this special island is home to a number of ancient monastic ruins, some dating back to the 5th century.

In order of size, Inchagoill measures 104 acres and is the fourth largest island on the lake. Today, Inchagoill is owned by the state and its national monuments are protected by the Department of the Environment.

In 1852, Sir Benjamin Lee Guinness purchased this island as part of the Ashford Castle estate. At that time, there were four families living on the island and these families were tenants on the estate.

Some family names included Kineaveys, O’Sullivans and Conways. In older times, there were as many as six families living on the island with other names including Murphy’s, Lydons and Butlers.

These families farmed 80 acres of land in the centre of the island with 24 acres of high trees as shelter all around. Two main factors led to the families leaving the island.

Firstly, isolation meant that medical care was a problem. Secondly, these people had better employment opportunities on the mainland. The last family to stay on the island were the Kineavys. They were a family of boat builders, and they could make a good living by building boats on the island. By 1935, there was only one inhabitant on the island, a man called Thomas Nevin.

When one walks up the little pathway from the pier on the island, the first building that comes into view is "Teampall Na Naoimh", translated as "The Church of the Saints". It is believed that this church was built by the Augustinian monks of Cong circa 1180AD. At that time, between monks and lay scholars, it is suggested that there were about 3,000 people in the monastery of Cong.

For this reason, the monks needed a place of peace and tranquillity to pray and meditate. Thus, the Church of the Saints was built.

The church is built of sandstone and its decorative doorway reflects at least three different European cultures. The archway of the doorway is Romanesque in style and it depicts the ten saints of Lough Corrib. On the outer and inner tiers of the doorway, at shoulder height are heads with platted beards, believed to be of Greek influence while the centre tiers display carvings of French design.

Just inside the doorway on the right hand side, one sees a Byzantine cross carved out on the wall. This cross was to be the inspiration for the Celtic cross that we know so well today.

This suggests that many monks and scholars came from abroad to study in the local monasteries. The altar of the church is situated at the eastern end of the building. In the 5th century, Ireland was a pagan country.

The early Christians who were trying to convert these pagans found that they worshipped the rising sun. By placing their alters to the east, the pagans who were still facing the rising sun became easier to convert to Christianity.

This church most likely had a thatched roof. The narrow splayed windows in the church both minimised rain and maximised daylight coming into the church.

The stone of Lugna and St. Patrick’s church are situated quite close to each other, about 100 metres west of "Teampall na Naoimh". More than any other monument on the island, the stone of Lugna has captured the attention of the most renowned archaeologists. The 5th century inscription on the stone which is still legible today reads "Lia Lugnaedon Macc Lmenueh".

This is written in old Gaelic and translates as follows: "The standing stone of Lugna son of Limanin". It is believed Limanin was one of St. Patrick’s sisters. It is also believed that St. Patrick and his nephew (also his navigator) came to Cong in the middle of the 5th century to spread the Christian faith.

The Pagan druids who were very powerful people at that time, had St. Patrick and his nephew banished to Inchagoill Island. This is how the island got its name – Inis an Ghaill (the island of the foreigner).

While building their church, Lugna died and was buried on the island. It is interesting to note that the stone has the shape of a boat’s rudder, which ties in with the theory that Lugna was St. Patrick’s navigator. Many archaeologists claim that this inscription is the oldest Christian inscription in Europe apart from one found in the Catacombs of Rome.

St. Patrick's words and deeds are only referred to in abstract in his own writings. Later biographers added to the information contained in the writings of St. Patrick but many of the details are contested.

According to later biographies he is recorded as entering the territory known as Cuil Toladh and erecting many churches. Other accounts suggest that he simply passed through the area that is now known as Cong after founding churches at Shrule and Kilmaine.

From the 6th Century, the local area increased in importance as a Christian centre. The first monastic settlement was founded in the 7th century and is believed to have been located to the south of the site of the present Abbey.

The townland that is presently known as Ashford was historically known as "Ceapach Chorcóige", the "plot of the beehives". This may refer to the beehive dwellings of the religious or their activities. According to tradition the first settlement was founded by St. Féchín of Fore. However, there are also contradictory claims that the settlement was founded by St. Molucci who may have been the first Abbot. St. Molucci is the saint associated with Cong in many early lives of the saints.

St. Féchín was associated with Cong in the work of John Colgan – Acta Sanctorum:

Hiberniae – but that association has been questioned by later authors on the grounds that it may have overstated any association the saint had with Cong or may have mistaken Cong in Mayo with a lesser known Cong at Ballysadare – the home of Féchín.

Féchín's association with Cong was further popularised in the historical writings of Roderic O'Flaherty during the 17th Century. According to a transcription of a title to the Abbey from 1501, Donnell, son of Hugh McAinmire gave a grant of land for the foundation of a monastery in the first year of his reign.

According to the Annals of the Four Masters “Domhnall, son of Aedh, son of Ainmire” became High King of Ireland in 624 AD. According to the Annals of Ulster, he became High King in 628 AD.

The first settlement is unlikely to have been a substantial presence and probably took the form of beehive cells and an oratory. Monastic settlements of this type may be seen on islands off the west coast of Ireland.

A monastic settlement on Árd Oileán off the coast of Connemara is an example of this type of settlement and is also associated with St. Féchín.

Nothing is known of the fate of the earliest monastic settlement but there is documentary and archaeological evidence that Vikings raided Lough Corrib in the 10th century and this may account for the disappearance of the early settlement. It is also possible that some form of simple monastic settlement continued to exist until the development of the Abbey in the 12th century.

A number of other local structures date from this period. For example, the souterrain at Lisheenard and many of the ringforts in the local area.

Their defensive nature suggests a need for protection at a time when Ireland was composed of a network of competing tuath – small kinship networks within larger kingdoms. And, as already mentioned, the west of Ireland was subjected to a number of raids by Vikings during this period.

During the 12th a more substantial monastic settlement was founded in Cong. We do not know exactly when the second Abbey was built. The first documentary record of the abbey is an account from the Annals of The Four Masters which indicated that in 1114 it was burned. The Annals refer to events at the Abbey throughout the 12th and 13th century.

The Abbey was at the heart of political and ecclesiastical power during the 12th century. It was associated with two High Kings of Ireland – Turlough O'Connor and Ruairi O'Connor.

The Abbey was also associated with the O'Duffy family who occupied senior ecclesiastical positions in Ireland during the 12th century and supplied many Abbots to Cong during the 13th century. Besides the royal connection, Cong also became one of the five bishoprics of Connacht between the Synod of Rathbresail in 1118 and the Synod of Kells in 1150.