In order not to have you enemy at the gate, you have to keep him at bay ... "
Cato the Elder
***
The meaning and origin of the expression: Keep at bay
Keep at bay
What's the meaning of the phrase 'Keep at bay'?
Prevent, either a person or an event, from advancing nearer.
What's the origin of the phrase 'Keep at bay'?
'Keep at bay' (sometimes used as 'hold at bay') is one of those expressions that we are likely to know the meaning of because we have picked it up from colloquial use in our youth and worked out the meaning from the context it was used in. The nature of how we learn language allows us to gain a knowledge of what an idiom means without necessarily knowing the meaning of the words contained in it - which I guess is why pages like this one get readers.
Anyhow, back to the phrase itself. It seems plausible that 'at bay' is a nautical phrase and that the allusion is to a ship that is anchored in a bay and waiting to enter a port. 'In the offing' has pretty much the same meaning. As it turns out, we only need one expression in English for that circumstance and 'keep at bay' derives from a completely different place.
Keep at bayThe Old French words 'abbay' or 'abai' mean 'barking'. These came into English, first as 'abay' and later as 'at bay'. Hounds that were barking were said in the 14th century to be 'at a bay'. This is recorded in the English romantic story Guy of Warwick, circa 1330:
Into a forest юat swine him ;ede. Into a ficke hegges he gan him hede. Юer he stod at a bay.
(A fat boar went into a forest. He hid in a thick hedge. He [the hound] stood there barking.)
Keep at bayTo keep at bay meant then to be in a standoff with a baying dog that was intent on killing - a scenario which also gave us the expression 'baying for blood'. In more placid moments hounds also 'bay at the moon'.
In recent times the phrase 'keep at bay' has taken on the more general meaning of 'fend off'. The earliest example that I can find of the modern 'keep at bay' (as opposed to 'at a bay') and which doesn't refer directly to hunting with dogs is from The Derby Mercury, February 1759, in a report of England's war with France:
We have seen the French kept at bay for the whole campaign, and they are gone into their winter quarters.
***
Cato the Elder
When Cato was very young, after his father's death, he inherited a small property in the Sabine territory, at a distance from his native town. There, he spent most of his childhood hardening his body by exercise, overseeing and sharing the operations of the farm, learning business and the rural economy. Near this land was a small hut abandoned after the triumphs of its owner Manius Curius Dentatus, whose military feats and rigidly simple character were remembered and admired in the neighborhood. Cato was inspired to imitate that character, hoping to match the glory of Dentatus.
Soon, an opportunity came for a military campaign in 217 BC, during the Second Punic War against Hannibal Barca. Experts express some disagreement about Cato's early military life. In 214 BC, he served at Capua, and the historian Wilhelm Drumann imagines that already, at the age of 20, he was a military tribune. Quintus Fabius Maximus Verrucosus had the command in Campania, during the year of his fourth consulship, and admitted the young soldier to the honour of intimate friendship. While Fabius communicated the valued results of military experience, he chose not to inculcate Cato with his personal and political values and preferences. At the siege of Tarentum, 209 BC, Cato was again at the side of Fabius. Two years later, Cato was one of the select group who went with the consul Claudius Nero on his northern march from Lucania to check the progress of Hasdrubal Barca. It is recorded that the services of Cato contributed to the decisive and important victory of Sena at the Battle of Metaurus, where Hasdrubal was slain. He later gave several vehement speeches which he often ended by saying "Carthago delenda est", or "Carthage must be destroyed."