In the phrase beggar my neighbour, beggar is a verb meaning to impoverish, from its literal sense to make a beggar of—cf. also meaning and origin of ‘to beggar belief’.

The phrase beggar my neighbour is used as a noun denoting a card game for two players in which the object is to acquire one’s opponent’s cards: players alternately turn cards up and if an honour is revealed, the other player must find an honour within a specified number of turns or else forfeit the cards already played.

By extension, the attributive adjective beggar-my-neighbour means relating to, or denoting, an advantage gained by one side at the expense of the other.

The earliest known mention of the card game called beggar my neighbour is from Poor Robin’s Almanack of 1734. This is the passage in which this mention occurs, as quoted in Volume II of Observations on the Popular Antiquities of Great Britain: chiefly illustrating the origin of our vulgar and provincial customs, ceremonies, and superstitions (London: Henry G. Bohn, 1854), by John Brand (1744-1806) and Henry Ellis (1777-1869)—the game names in this passage are used allusively, but the allusions are now unintelligible:

The lawyers play at beggar my neighbour; the new-marry’d young couples play at put; the doctors and surgeons at thrust out rotten, but if they meet with a man that is so eat up with the pox that he is all compos’d of that sort of metal, they thrust out all together; the farmers play at My Sow’s pigg’d; the schoolmasters play at questions and commands; and because every man ought to mind his business, he that plays most at all sorts of gaming, commonly at last plays a game at hide and seek, and cares not to leave off till he has got the rubbers.

In the same manner, in the following from The British Chronicle. Or, Pug’s Hereford Journal (Hereford, Herefordshire, England) of Thursday 23^rd August 1781, the allusions are now incomprehensible:

In this playing age, we find that the following powers and persons are thus employed:
France, Spain, Holland, and America, playing Quadrille.
The Emperor of Germany at Traffick.
The Empress of Russia at Whist.
The King of Great-Britain at Brag.
Admiral Rodney at Vingt-un.
The Statia captors at Piquet.
The India Directors at Beggar-my-neighbour.
The Government Contractors at Cribbage.
Alderman Wilkes at Five and forty.
Lords Cornwallis and Rawdon at Back-gammon.
The West-India merchants at Hazard.
General Elliot at Ball.

Likewise, all the other allusive uses that I have found of beggar my neighbour up until 1832 (in the below-quoted passages from Felix Farley’s Bristol Journal) explicitly allude to the card game—with, however, one exception: Beggar my Neighbour; or, A Rogue’s a Fool is the title of a comedy performed in July 1802 at the Theatre Royal, Haymarket, London; The Morning Post and Gazetteer (London, England) of Monday 12^th July 1802 explained the plot of this comedy:

THEATRE,
HAY-MARKET.

A new Comedy, in three acts, intitled, “Beggar My Neighbour,” was performed here on Saturday night. One of its principal characters is Dalton, a roguish Attorney, who seeks to convert the foibles and misfortunes of his neighbours to his own advantage. We presume the piece derives its title from this circumstance, for though its poverty in respect of merit intitles it to a beggarly name, any consideration of that kind probably never entered into the mind of the author. Among the various persons of whom Dalton would take advantage, is Mr. Winnington, a gentleman in his vicinity, of supposed opulence, but who is suddenly involved in difficulties, by the misfortune of a banking-house, in which he is a partner. The piece commences with this incident, and is followed up by several scenes, in which Dalton, determined upon the ruin of Winnington, and the ultimate possession of his only daughter Harriet, prevails on Henry Evelyn, her lover, to withdraw his whole fortune from the firm of Winnington, in which it was vested. Henry, a dissipated, but a good natured young man, requests that no harshness shall be used in this proceeding. Dalton, however, regardless of the instructions, proceeds in the rudest and most cruel manner. Philip Evelyn, the brother to Henry, a youth of a grave, sentimental character, now interferes, but in vain, to extricate Winnington from his difficulties. At length Henry is apprised of the baseness of Dalton, and offers a complete discharge. This Winnington rejects, conceiving Henry to be his wilful persecutor. The latter is then obliged to effect the relief of Winnington by stratagem, and an explanation having taken place, in which the character of Henry appears in its true light, Winnington is reconciled, and bestows upon him the hand of Harriet.

A pun on the phrase as used in the title of this comedy appeared in the same issue of The Morning Post and Gazetteer:

The new comedy of Beggar my Neighbour, is an old play acted by France during the war.

The second-earliest occurrences that I have found of the phrase used figuratively and without explicit reference to the card game are from the column From themaninthemoon [sic], in Felix Farley’s Bristol Journal (Bristol, England) of Saturday 29^th September 1832 and Saturday 20^th October 1832—these are also the earliest uses of the attributive adjective beggar-my-neighbour that I have found:

– Saturday 29^th September 1832:

I am happy to find “Hope tells a flattering tale.” He is right to tell the people, and may he convince them, that “trade, commerce, and agriculture must flourish or decay together.” But what strange mistakes the deluded make on these subjects! Foolish to believe that the “beggar-my-neighbour” system can do any one good, but the scramblers”!

– Saturday 20^th October 1832:

The beggar-my-neighbour system is a wretched one indeed;—ruin master, ruin man.

The earliest figurative use that I have found of the variant phrase beggar thy neighbour is from The New Age (Buffalo, New York, USA) of Saturday 29^th December 1917:

It is no secret that in Great Britain, with war at her very door, bread and meat are both selling at a lower price than in the United States. And this despite the fact that many cargoes destined for the ports of that country have been wantonly destroyed in the hellish game of twentieth century warfare which should be fitly named “beggar thy neighbor.”

On Saturday 30^th July 1932, the Surrey Advertiser and County Times (Guildford, Surrey, England) reported that during a meeting of the Guilford Town Council,

Mr. V. G. Wilkinson said that [he] did not believe in a policy of “beggar thy neighbour.”

The earliest use that I have found of the attributive adjective beggar-thy-neighbour is from See Leadership as Nation’s Task, published in The Milwaukee Journal (Milwaukee, Wisconsin, USA) of Monday 17^th February 1941:

America must abandon her policy of isolation and assume leadership of the world if there is to be a lasting peace, Father Bernard W. Dempsey, S. J., an economist, said in a lecture Sunday afternoon at the Marquette university medical school auditorium.
“Imperialistic Europe could have been reconstructed in 1918 had America then imposed and enforced a peace that might have been unpleasant at the time but understandable to nations who lived with a ‘beggar thy neighbor’ policy,” Father Dempsey said. “But America refused to become involved, so 20 years of unheard of disorder in international affairs has followed.”

 

The following photograph and caption are from The Coventry Evening Telegraph (Coventry, Warwickshire, England) of Monday 13^th March 1967:

June Whitfield and Peter Jones as the Garveys in a comedy series which begins on B.B.C.-1 at 7.30 […].
In “Beggar My Neighbour” the Garveys have the problem of “keeping up with the Joneses,” in their case their next-door neighbours and relatives, the Butts.
The Garveys’ basic problem is that they have less money than their neighbours and their arguments, whether over holidays or owning a car, come back to this point.