Gowran was already old when the Normans arrived in 1169. The kings of Ossory had a residence here; the place was known as Belach Gabhrán, the pass of Gabhrán, on a natural east-west route between the Nore and Barrow valleys. The Battle of Bealach Gabhrán was fought in 754. By 938 the surrounding area was part of the ancient cantreds of Oskelan and Ogenty, held by the O Dunphy clan under the Mac Giolla Phádraig rulers of Ossory. The ogham stone in St Mary's Church, carved sometime in the third or fourth century with a memorial inscription and later marked with a Christian cross, is the surviving evidence that this site was sacred well before St Patrick's recorded visit in 455 AD.

After the Norman Invasion of 1169, the Manor of Gowran - 44,000 acres - was granted to Theobald FitzWalter, who became the first Chief Butler of Ireland and the ancestor of all subsequent Butlers and Ormondes. He incorporated the town sometime after 1177 and died in 1206. His descendant James Butler, third Earl of Ormond, built Gowran Castle in 1385, made it his usual residence, and styled himself the Earl of Gowran. Town walls went up around 1415, and a Magdalen hospital was built outside them in 1578 to care for those with leprosy. The thirteen-kilometre cluster of Gowran town, castle and church represents one of the densest concentrations of intact medieval Irish urban fabric anywhere in the country.

In the spring of 1650, with Cromwell's army marching through Munster and Leinster, Gowran was held by a Royalist garrison under Colonel Robert Hammond - a cousin of Cromwell, on the wrong side of the family quarrel. The garrison surrendered after a brief siege and accepted Cromwell's offer of quarter. Cromwell then ordered all but one of the officers shot by firing squad. A Catholic priest captured in the castle was hanged. It was the kind of selective brutality that Cromwell used as policy: spare the soldiers, who might still be useful; execute the officers, who would not bend; kill the priests, because their deaths were politically clean. The town survived. The castle did not. Three centuries of Agar tenure followed.

St Mary's Collegiate Church Gowran was the Butlers' mausoleum for a hundred and fifty years. James Butler, first Earl of Ormond, who died in 1338, lies here with his wife Eleanor de Bohun - granddaughter of Edward I of England, niece of Edward II - the two effigies still preserved in the chancel. So do the second and third Earls, James and James, and their ancestor Edmund Butler, Earl of Carrick, who died in London in 1321 on his way back from the pilgrimage shrine of St James at Santiago de Compostela. His body was brought home and buried here on 10 November 1321. The Single Butler Knight Tomb, carved between 1500 and 1515, is attributed to the O'Tunney workshop - the Kilkenny stonemasons who produced some of the best medieval Irish carving. The Christianised ogham stone, the effigy of Ralph the portrieve dated 1253 (believed to be the oldest dated burial monument in Ireland), and the assembly of medieval Butler tombs together make this one of the finest small medieval churches in the country.

Gowran Park racecourse opened on 16 June 1914 and has run National Hunt and flat meetings ever since. Its signature race is the Thyestes Chase, sometimes called the Grand National of the South - a 3-mile chase run in late January. It has been won by three of the greatest steeplechasers in history: Arkle in 1964 (himself a three-time Cheltenham Gold Cup winner and arguably the greatest jumper ever foaled), Hedgehunter (who would go on to win the Aintree Grand National in 2005), and Numbersixvalverde (Aintree winner in 2006). In 1914 the racecourse sat within the Annaly Estate, owned by Lady Annaly - born Liliah Agar-Ellis of Gowran Castle, who became known as Lady Annaly through her marriage to Luke White, the third Baron. Her father had owned Surplice, who won the Epsom Derby and the St Leger in 1848. Racing runs in the demesne walls themselves.

Arundel Elias Disney left Gowran in the 1830s, emigrating first to Ontario, Canada, where the family eventually put down roots before later generations moved to the United States. So did thousands of others, in the Famine years and after - the small streets of the town today preserve the names of families who simply ended, locally, sometime in the nineteenth century. Mary Butler, of the Butlers of Neigham just outside Gowran, married a man named Benjamin Yeats in Tullamore in 1773; her great-great-grandson William Butler Yeats won the Nobel Prize for Literature in 1923. D. J. Carey, born here in 1970, became one of the greatest hurlers of his generation, a Kilkenny icon who retired in 2006 having won most honours the game offers. Colonel Dan Bryan, head of the Irish Army's intelligence directorate G2 during the Second World War, was born in Dunbell, just outside Gowran, and ran Irish counter-intelligence operations - including the careful management of German spies on Irish soil - from a small office in Dublin. For a town of perhaps a thousand people, that is a high diaspora.