Widely regarded as one of the greatest Irish-language novels of the 20th century, An Béal Bocht is a classic satire in Irish by one of the century's great writers. This extremely funny book, with its rain-sodden peasants of Corca Dorcha who combine pretensions to proficiency in English with true caint na ndaoine in the hope of impressing the insatiable Irish-language enthusiasts, was the proof that the Irish of the Revival had come of age. It earned Flann O'Brien the accolade bestowed upon him by Austin Clarke: 'our Gaelic satirist' and is still a useful corrective against the native tendency to take things too seriously.

As its subtitle, An Milleanach, indicates, it satirises Tomas Ó Criomhtháin's famous Blasket autobiography An t-Oileánach as well as other Gaeltacht works like Caisleáin Óir by Donegal writer Séamus Ó Grianna.