Another method of exerting authority, available to all members of Celtic society, was the ritual fast—the troscad. As a legal form of redressing a grievance, this act emerged in the Brehon law system. That it was an ancient ritual can be demonstrated by the fact that it bears almost complete resemblance to the ancient Hindu custom of dbarna. This custom is not only found in the Laws of Manu but as prayopavesana ('waiting for death') it occurs in ancient Vedic sources. Dr Joyce saw the troscad as 'Identical with the eastern custom, and no doubt it was believed in pagan times to be attended by similar supernatural effects'; that is, that if the one fasted against ignores the person fasting then they would suffer fearful supernatural penalties. The troscad was the means of compelling justice and establishing one's rights. Under law, the person wishing to compel justice had to notify the person they were complaining against and then would sit before their door and remain without food until the wrongdoer accepted the administration or arbitration of Justice. 'He who disregards the faster shall not be dealt with by God nor man ... he forfeits his legal rights to anything according to the decision of the Brehon.'

The troscad is referred to in the Irish sagas as well as laws and when Christianity displaced the pagan religion, the troscad continued. We find St Calmin fasting against Guaire the Hospitable, St Ronan fasting against Diarmuld, even Patrick himself fasting against several persons to compel them to Justice. Some people even fasted against the saints themselves to get them to give justice and wives also fasted against their erring husbands.

It is fascinating, as well as sad, that in the long centuries of England's sorry relationship with Ireland, the Irish have continued a tradition of the troscad which has become the political hunger strike. One of the most notable Irish political hunger strikes was that of the Lord Mayor of Cork, Terence MacSwiney, also an elected Member of Parliament, who was arrested by the English administration in Cork City Hall and forcibly removed from Ireland to London's Brixton Prison. He died in Brixton on 24 October 1920, on the seventy-fourth day of his hunger strike. He was, of course, not the first Irish political prisoner to die on hunger strike during this period. Thomas Ashe died as a result of forcible feeding on 25 September 1917. MacSwiney's sacrifice was said to have inspired Mahatma Gandhi to revive the custom of dbarna in India as a moral political weapon. In recent times, and perhaps better known, came the hunger strikes in Long Kesh prison camp in Northern Ireland, when in 1981, ten Irish political prisoners died on hunger strike in an attempt to force the administration to restore their rights as political prisoners, taken away from them in 1974. Among them was Bobby Sands, elected Member of the British Parliament, and Kieran Doherty, elected Member of the Irish Parliament. But these ten Irish prisoners were not the first to resort to the continuing tradition of the troscad in an attempt to assert their rights during the current struggle in the north of Ireland, nor the first to die on hunger strike. Frank Stagg, for example, died after a sixty day hunger strike in Wakefield Prison on 12 February 1976, trying to compel the reinstatement of recognition of special status withdrawn in 1974. The troscad was never entered into lightly and always with full knowledge of the seriousness of the final intent.

The troscad in ancient times was the effective means of someone of lesser social position compelling Justice from someone of higher social position. Thus Druids could fast against a king, or even a man or woman in the lower order of society could fast against their chieftain.

 
From Ellis, Peter Bereford. The Druids (Eerdmans, 1998). pp. 141-142.