The name used by the early annalists to denote Ballyshannon, was Athseanaigh, which signified the “Ford of Seanach,” who was ancestor of the Princes of Tirconnell. “Bel” stands for mouth, and the modern designation is a corruption of the Celtic name meaning “the entrance to Seanach’s ford.”

The town is situated on both sides of the river Erne, about eleven miles south-south-west of the town of Donegal, to the extreme south of the county.

The castle was on the north bank of the river, and commanded the principal ford. For this reason its possession was of immense strategical importance, it being the key to the province of Tirconnell. Of the great fortress of the O’Donnells only a small portion of one of the walls remains. This is on the north side of the market yard, part of it being incorporated with a grain store and part with a butter shed. It is 10 feet high and 5 feet thick.

The fortress originally occupied the whole of the market square, and it is most likely that its stones were used in the erection of a cavalry barracks, which subsequently occupied the present market enclosure, but which has now been removed.

Round the castle stretched a beautiful park, the name being still preserved in some old leases. This extended almost to the summit of the hill on the north. Quantities of human bones have been found in the neighbourhood.

The castle was erected in 1423 by Niall, son of Turlough O’Donnell. In 1435 Naghtan O’Donnell gave it to Brian Oge O’Neill for promising him assistance against the O’Neill. Brian, however, went treacherously to his chief without O’Donnell’s knowledge, leaving his warders in the castle. O’Neill, not approving of such double dealing, took him and his two sons prisoners, cutting off a hand and a foot from each, under which treatment one of the sons died.

The fortress was taken from O’Donnell’s warders in 1496 by his son Hugh. His brother Con, with the assistance of Maguire, laid siege to the castle and dislodged him. O’Neill possessed himself of the stronghold in 1522, and slew the warders. It seems to have remained in his possession until Sir Henry Sidney came north in 1566 and had it delivered to him, as well as the castles of Donegal, Beleek, Bundrowes, and Castle Sligo. All these fortresses he placed in the hands of O’Donnell and his allies, who were at this time in high favour with England.

The next year Shane O’Neill liberated Con O’Donnell and his brother, who were at the time his prisoners, and the castles of Ballyshannon and Beleek were delivered to Con.

About this time the Government began to look with alarm on the growing power and popularity of the O’Donnells, and the State Papers of the period contain notes regarding the advisability of garrisoning Ballyshannon and the other fortresses of Tirconnell.

The regular military force under O’Donnell consisted of 1,500 foot and 300 horse, out of which the garrison of Ballyshannon numbered 200 foot soldiers and 40 mounted men.

In 1584, Lord Deputy Perrot recommended the erection of a castle and bridge at Ballyshannon, no doubt to counteract the power of the O’Donnells’ fortress, which could hold the main ford against all comers. Four years later the Lord Deputy dates a letter from Ballyshannon, and about this time young Hugh O’Donnell was kidnapped and imprisoned in Dublin Castle.

In 1592, Mr. Ralph Lane applied to Burghley, asking for the custodianship and fee-farm of the castle and lands of Ballyshannon, &c. The successful escape of Red Hugh, however, from Dublin Castle seems to have placed the possibility of the Government’s disposing of his ancestral home quite out of the question, and in 1592 the greatest of the O’Donnells received a most royal welcome from his father’s dependents in the north.

Arriving at Ballyshannon, where the O’Donnell warders still guarded the fortress, the whole country flocked to meet him and offer their congratulations on his escape.

The neighbourhood was in the most fearful state, being entirely overrun by freebooters, against whom even the English were powerless—the castles of Ballyshannon and Donegal alone remaining in the hands of the O’Donnells.

After a most successful campaign against the marauders, Hugh O’Donnell returned to Ballyshannon to undergo medical treatment for his feet, which had been fearfully injured by travelling from Dublin to Glenmalure in his house-shoes over the mountains and in bitter cold. He did not recover entirely until the end of the year, as both his great toes had to be amputated.

In 1594 Sir Ralph Lane, writing to Burghley, mentions that Hugh Roe O’Donnell would have broken down Ballyshannon but that his mother dissuaded him from it, assuring him that it might be defended with his own forces. Yet this very year it was evidently in the hands of the O’Donnells, and remained so until its capture in 1602.

The State Papers of this period are full of letters requesting money and forces sufficient to take it, alleging that the fortress was the “key of the province,” and no peace could be hoped for in the north until it was garrisoned by English.

In the meantime the O’Donnells lived in royal state, and with lavish hospitality entertained the surrounding chiefs, while their flag floated from the battlements.

Sir George Carew observes of the Prince of Tirconnell: “O’Donnell is the best lorde of fishe in Ireland, and exchangeth fishe allwayes with foreign merchants for wyne, by which his call in other countryes is the kinge of fishe.”

It was during a great assemblage of chiefs at Ballyshannon to organise a raid on the English border, that the great Shane O’Neill became madly enamoured of O’Donnell’s lovely daughter, Helen. He went to her father and demanded her hand, but was informed that the lady was already betrothed to Maguire, the young chieftain of Fermanagh, who held his lands under suzerainty of O’Donnell. This young man had been educated at the Spanish court, and was all that a maiden could wish in a suitor.

One evening the lovers left the castle together, for a stroll by the river side, towards Belleek. Here, while Helen was singing to her harp, O’Neill, who had followed them, broke in upon their happiness. Maguire drew his sword to defend the lady, but he was no match for the great chief from whom he quickly received his death wound. O’Neill placed the fainting form of the fair Helen before him on his horse, and, with a few followers, rode to Dungannon Castle. Her father at once called his forces together, and followed to revenge the injury. The end of the story has several variations, but the most probable seems to be that O’Neill, finding the beautiful girl irreconcilable to the loss of her handsome lover, returned her to her father. The world had, however, lost its charm for her, and the rest of her short life was spent in seclusion.

In 1597 the first determined attack was made on Ballyshannon. Sir Conyers Clifford, Governor of Connaught, with four thousand men, foot and horse, marched on the stronghold, accompanied by Donough, the son of Connor, Murragh, Baron of Inchiquin, and other Irish nobles. O’Donnell having all the fords guarded, they were obliged to cross the river about half a mile west of Belleek. Here the Baron of Inchiquin was shot through his armour, while his horse was standing in the deep water below the ford, where he was encouraging the soldiers and saving them from drowning.

The ordnance was landed by water and planted against the castle. The siege lasted three days, but when the little garrison were thinking of surrendering, help arrived from Tyrone, and the English were driven off with great loss. The defenders of the castle numbered only eighty men, and were commanded by a Scotchman named Owen Crawford.

During Red Hugh’s absence in Spain in 1602 the English took the opportunity to again attack the fortress. The warders, seeing no hope of relief, fled, after the walls had been battered by a big gun, and Captain Digges took “that long desired place.”

Ballyshannon, with 1,000 acres, was reserved to the King in 1603, and five years later Sir Henry Folliot was appointed Governor. In this year the plot to seize the King’s castle of Ballyshannon was one of the charges in the indictment against the Earls of Tyrone and Tirconnell. In 1610 the castle, lands, and fishings were granted to Sir H. Folliot for twenty-one years. He was raised to the peerage under the title of Baron Folliot of Ballyshannon, 1619.

During the Jacobite troubles the castle was still used as a military headquarters, and the town was for a time in the hands of the Royalists.

The land on which the ancient fortress stood is now part of the Connolly estate, and was acquired by purchase from the Folliots.