The town is just off the M8 route from Dublin to Cork. Cashel is particularly renowned for the Rock of Cashel, a site hosting a ruined church and fortifications, formerly the seat of the Irish kings of Munster.
In the 4th century, the Eóganachta dynasty founded their capital on and around the rock. In the times following, the kings of Munster reigned here. Saint Patrick is believed to have baptized Cashel's third king, Aengus, though it is more likely to have been Palladius. In 977 the Dál gCais usurper, Brian Boru, was crowned here as the first non-Eóghanacht king of Cashel and Munster in over five hundred years. In 1101 his great-grandson, King Muircheartach Ua Briain, gave the place to the bishop of Limerick, which also denied it forever to the MacCarthys, the senior branch of the Eóganachta. The bishops had a very famous school in Cashel and sent priests all over the continent, especially to Regensburg in Germany, where they had their own monastery, called Scots Monastery.
The Rock of Cashel is now one of Ireland's most popular tourist sites. The town has many other interesting attractions, including the GPA Bolton Library (which houses many books found nowhere else in the world).
The Heritage Centre & Tourist Office on Main Street (admission free) displays a model of Cashel in the 1640s and a multimedia presentation in several languages, and sells Tipperary crafts.
Walking is the best way to discover the Heritage Town of Cashel, the Georgian St. John's Cathedral (which replaced that on the Rock in the eighteenth century) and its adjacent Bolton Library, city walls, and the former Deanery or archbishop's palace which is now a leading hotel. Town centre car parking off Main Street.
Cashel is home to the Museum of Rural Life.
Brian Boru fortified Cashel in 990. Murtagh O'Brien, King of Cashel, in presence of the chiefs and clergy, made a grant in 1101 of the "Rock" with the territory around it to O'Dunan, "noble bishop and chief senior of Munster", and dedicated it to God and St. Patrick. Then Cashel became an archiepiscopal see, and O'Dunan its first prelate as far as the primate, St. Celsus, could appoint him. At the synod of Kells, 1152, Cardinal Paparo gave a pallium to Donat O'Lonergan of Cashel, and since then his successors have ruled the ecclesiastical province of Munster. In 1127 Cormac MacCarthy, King of Desmond, erected close to his palace on the "Rock" a church, now known as Cormac's Chapel, which was consecrated in 1134, when a synod was held within its walls. During the episcopate of Donal O'Hullican (1158–1182), the King of Limerick, Donal O'Brien, built in 1169 a more spacious church beside Cormac's Chapel, which then became a chapterhouse.
The "City of Kings" had a full share in the vicissitudes of the times. Maurice, a Geraldine, filled the see from 1504 to 1523, and was succeeded by a natural son of Pierce, Earl of Ormond, Edmund Butler, prior of Athassal Abbey. In addition to the wars between the Irish and the English there arose a new element of discord, the Anglican Reformation introduced by Henry VIII Tudor. While residing at Kilmeaden Castle Archbishop Butler levied black-mail on the traders of the Suir, robbing their boats and holding their persons for ransom. At a session of the royal privy council held at Clonmel in 1539, he swore to uphold the spiritual supremacy of the king and denied the power in Ireland of the Bishop of Rome. He died 1550 and was buried in the cathedral. Roland, a Geraldine (1553–1561), was created archbishop by the Roman Catholic English Queen Mary. After a vacancy of six years Maurice FitzGibbon (1567–1578) a Cistercian abbot was promoted to the archbishopric by pope Pius V, but James MacCaghwell was put forward by Elizabeth I of England. Thus began the Anglican religion at Cashel. FitzGibbon, who belonged to the royal Desmond family, being deprived of his see, fled to France and passed into Spain where he resided for a time at the Court. He conferred with the English ambassador at Paris in order to obtain pardon for leaving the country without the Queen's sanction, and to get permission to return. In this he failed, and going back to Ireland secretly he was arrested and imprisoned at Cork, where he died in 1578. On the death of MacCaghwell, Elizabeth advanced Miler MacGrath, a Franciscan and Bishop of Down, to the See of Cashel. He held at the same time four bishoprics and several benefices, out of which he provided for his numerous offspring. Having occupied the see for fifty-two years, he died in 1622. His monument in the ruined cathedral bears an epitaph written by himself.
Dermod O'Hurley of Limerick, a distinguished student of the university of Louvain in the Duchy of Brabant and professor at Reims in France, was appointed in 1581 by pope Gregory XIII. Having presided over the Roman Catholic diocese secretly for two years, he was discovered and brought before the Lord Justices at Dublin, was tortured upon his refusal to take the Oath of Supremacy to the English crown and was subsequently hanged outside the city in 1583. Dr Butler 2nd (1774–1791), on being appointed to the Roman Catholic diocese, settled in Thurles, where the Roman Catholic archbishops since then have resided. His successor, Archbishop Bray (1792–1820), built a large church in the early part of the nineteenth century, on the site of which Archbishop Patrick Leahy (1857–1874) erected a splendid cathedral in Romanesque style. It was completed and consecrated in 1879 by Archbishop Croke (1874–1902) and dedicated to Our Lady of the Assumption.
The Anglican archbishopric was reduced in status by legislation of 1833 and the bishopric combined initially with Waterford. St Albert (feast January 8), a reputed former bishop, is the patron saint of the Roman Catholic diocese. The Archbishop of Cashel is Administrator of the ancient Diocese of Emly.