The phrase to beard the lion in his den, or in his lair, means to confront or challenge someone on their own ground.
This phrase stemmed:
1–: partly from the idea of daring to grab a lion by its “beard”, as in the King James Version (1611) of the First Book of Samuel, 17:35:
34 And Dauid said vnto Saul, Thy seruant kept his fathers sheepe, and there came a Lyon, and a Beare, and tooke a lambe out of the flocke:
35 And I went out after him, and smote him, and deliuered it out of his mouth: and when he arose against me, I caught him by his beard, and smote him, and slew him.
2–: partly from the use of the verb beard in the sense to boldly confront or challenge, as in the following passage from The history of Henrie the fourth [Part 1] (Quarto 1 – London, 1598), by the English poet and playwright William Shakespeare (1564-1616):
– Percy. By God, I cannot flatter, I do defie
The tongues of soothers, but a brauer place
In my harts loue hath no man then your selfe,
Nay taske me to my word, approue me Lord.
– Douglas. Thou art the King of honor,
No man so potent breaths vpon the ground,
But I will beard him.
3–: partly from the figurative use of the noun beard in the sense of face, as in obsolete phrases such as:
– maugre somebody’s beard, meaning in defiance of, or in direct opposition to, somebody’s purpose,
– to be, or to meet, in somebody’s beard, meaning to oppose somebody openly and resolutely.
The phrase seems to have originated in Scotland; it is first recorded as to beard the lion in The Regicide: Or, James the First, of Scotland. A Tragedy (London, 1749), by the Scottish author Tobias George Smollett (1721-71):
When the Battle joins,
Thou shall be answer’d.—
When the Battle joins!—
—Away, Dissembler!—Sooner would’st thou beard
The Lion in his Rage, than fairly meet
My Valour on the Plain!
The first known user of the extended form of the phrase was also a Scottish author, viz. the poet and novelist Walter Scott (1771-1832) in Marmion; A Tale of Flodden Field (Edinburgh, 1808):
On the Earl’s cheek the flush of rage
O’ercame the ashen hue of age:
Fierce he broke forth:—“And dar’st thou then
To beard the lion in his den,
The Douglas in his hall?
And hop’st thou hence unscathed to go?”
In early use, the phrase alluded to Marmion, so much so that—in its ‘original poetry’ section ironically—The Morning Post (London, England) of Thursday 8th August 1811 published O’Connor.—An heroic poem. Part the second, in which the anonymous author plagiarised Walter Scott:
On Connor’s cheek the flush of rage
A dreadful storm seem’d to presage,
Fierce he broke forth; “and dar’st thou then
To beard the lion in his den,
O’Connor in this house?
The earliest use that I have found of the phrase without reference to Walter Scott’s poem (without even quotation marks) is from a letter by a person signing themself ‘Verax’, published in The Morning Chronicle (London, England) of Saturday 6th December 1817; the author examined the problems that would arise if the Heir Apparent to the Throne was holding the office of Commander in Chief:
Let us suppose the personage next in succession to the Throne presiding over the military departments, and (as Royal minds are as liable to weakness and error as inferior ones) that, from some cause or other, the functions of the office are not performed with the industry and accuracy in that arduous situation eminently requisite; that the interests of the army suffer; that its equipments are imperfect, its discipline relaxed; that the brave veteran who has fought and bled in the defence of his country, sees the legitimate rewards of his services bestowed on high-blooded youth and inexperience; that money, not merit, regulates the scale of promotion. In such a state of things where is the remedy to be found ? In Parliamentary investigation? Who will have the hardihood to explore the source of such abuses? Who will dare to raise the veil that covers the errors in conduct, perhaps only the defect of talent, and imbecility of intellect of the Heir Apparent ? Who will be so irreverent as to expose to the general gaze of vulgar curiosity the indolence, neglects, mistakes, delinquencies of his future King? Who will be so indecent as to set about proving to the country, the criminality or incapability of her next Sovereign? Who will brave the overwhelming torrent of princely indignation, swollen and impelled by the terrors of military power? Who will beard the lion in his den? Who will treasure up for himself the wrath to come of exasperated, insulted majesty?
Through the translation of Marmion; A Tale of Flodden Field, the phrase was borrowed into French as braver le lion dans sa tanière, meaning to defy the lion in its den. (Conversely, the lion’s share was borrowed from the French expression le partage du lion.)
In Marmion. Histoire tirée de la bataille de Flodden-Field (Paris, 1832), the translation by Albert Montémont (1788-1862), the above-quoted passage is as follows:
L’étincelle de la rage colora soudain la joue du vieux comte, qui aussitôt lui répondit fièrement : « Oses-tu donc braver le lion dans sa tanière et le Douglas dans son château ? Espères-tu en sortir sain et sauf ? »
The French novelist Eugène Sue (Marie-Joseph Sue – 1804-57) used both braver le lion dans sa tanière and the variant braver le lion dans son repaire (repaire is a synonym of tanière) in La clochette d’airain, ou Le chariot de la mort. An 56 à 40 avant Jésus-Christ, published in the first volume (Paris, 1849) of Les mystères du peuple ou Histoire d’une famille de prolétaires à travers les âges.