The phrases parting shot and Parthian shot denote a sharp, telling remark, act, gesture, etc., made in departing.

The phrase parting shot denotes, literally, the final shot fired at the moment of departure [cf. for example quotation 1.2 below].

The phrase Parthian shot refers to the Parthian ¹ horsemen’s habit of shooting arrows backwards while in real or pretended retreat.

¹ The ancient kingdom of Parthia lay south-east of the Caspian Sea in present-day Iran; from c.250 BC to c.230 AD, the Parthians ruled an empire stretching from the Euphrates to the Indus.

The English poet and playwright William Shakespeare (1564-1616) alluded to the Parthian horsemen’s tactics in The Tragedie of Cymbeline (London: Printed by Isaac Jaggard and Edward Blount, 1623):

Boldnesse be my Friend:
Arme me Audacitie from head to foote,
Orlike [sic] the Parthian I shall flying fight,
Rather directly fly.

A more recent allusion to the Parthian horsemen’s tactics occurs in the following from the Washington Gazette (Washington, D.C.) of Monday 24^th May 1824:

When Mr. Edwards, like the flying Parthian, shot his poisoned arrows at Mr. Crawford, the editor of the National Gazette was one of those who pronounced Mr. Crawford’s character and prospects to be fatally wounded.

In view of the resemblance between the phrases parting shot and Parthian shot, it has been conjectured that one is an alteration of the other. However, parting shot and Parthian shot may have developed independently from each other. Additionally, it cannot be inferred from the fact that the earliest occurrences of parting shot that I have found slightly predate those of Parthian shot that the latter phrase is an alteration of the former.

 

1-: PARTING SHOT

 

These are, in chronological order, the earliest occurrences of the phrase parting shot that I have found:

1.1-: From the translation from German of a correspondence from the neighbourhood of La Fère, in northern France, originally published in the Rheinischer Merkur (Rhenish Mercury – Koblenz) of Monday 28^th August 1815; this translation was published in several British newspapers on Monday 11^th September 1815—for example in The Times (London, England):

The little fortress of Lafere […] is still occupied by the enemy, but closely surrounded by our troops, and is so quiet, that we should know nothing about it did it not thunder every morning during our morning prayers, to wake its sleepers; and had it not the civility to wish us good night every evening by a parting shot.

1.2-: From Narrative of a voyage, in His Majesty’s late ship Alceste, to the Yellow Sea, along the coast of Corea, and through its numerous hitherto undiscovered islands, to the Island of Lewchew; with an account of her shipwreck in the Straits of Gaspar. By John M’Leod, surgeon, of the Alceste (London: John Murray, 1817):

They [= the Malay pirates] had taken some measure to sink their proa ², for she went down almost immediately. […] The consort of this proa, firing a parting shot, bore up round the north end of the island, and escaped.

² The noun proa denotes a Malay undecked sailing boat, usually with a large triangular sail and a canoe-like outrigger.

1.3-: From the account of a court case, published in several British newspapers on Thursday 7^th August 1817—for example in The Times (London, England):

An altercation ensued, in which the plaintiff said “that the defendant was no gentleman to take away his property in that manner.” The defendant replied, “You d—d Jew-looking scoundrel, if it was not for such fellows as you we should have no thieves;” and immediately took up the shirt, and was going off with it, when the plaintiff (determined to have a parting shot) called him “a d—d rascal.”

 

2-: PARTHIAN SHOT

 

These are, in chronological order, the earliest occurrences of the phrase Parthian shot that I have found:

2.1-: From The Fraudulent Franking, published in the Washington Gazette (Washington, D.C.) of Thursday 10^th October 1822—the author comments on a letter published in the Richmond Enquirer of Tuesday 8^th October 1822:

At the heel of the letter its real object is visible: the writer had no reasonable hope of rsecuing [sic] from merited reproach the characters of those implicated in the fraudulent franking, but he has availed himself of the opportunity (however abrupt) to direct a Parthian shot at the Treasury.

2.2-: From The Morning Chronicle (London, England) of Tuesday 9^th November 1824:

The Lord Chancellor seized an occasion the other day to take a Parthian shot at the important question respecting the publication of Reports, which has lately occupied so much of the public attention.

2.3-: From the Washington Gazette (Washington, D.C.) of Thursday 29^th September 1825:

If ever the interests of the South required wise counsels in the National Legislature, it is at this crisis: not the silly and passionate counsels of interested partizans and office-hunters, where declamation and invective postpone the calmness of deliberation, and may precipitate the very measures which the soundest policy of the South ought, by all means, to avert. The Parthian shot from Mr. King will not be forgotten; and must be met by a combination of knowledge and sagacity, and measures adopted to keep sacred, from the assaults of the North, the Slave property of the South.

2.4-: From an article published in several British newspapers on Wednesday 2^nd May 1827—for example in the Evening Mail (London, England):

Let the ex-Ministers of the House of Lords beware how they indulge their numerous enemies, by risking a disclosure of the feelings which instigated them to resign. Nobody wants their explanation—no wise man is the least curious to ascertain the cause of a consequence so infinitely pleasing. As for the amateur defenders of the resignation,—viz., Lord Ellenborough (the brother-in-law of the late Lord Londonderry), and the present Marquis of that title—what brings them into the fray we wonder? People say that they both are inclined to fire, in retreating, one valedictory shot at His Majesty’s Prime Minister; but “Thrice is he armed that hath his quarrel just,” ³ &c., &c.
In the meantime, talking of these Parthian shots, what will be said, or can be thought of that nondescript order from the Horse Guards, signed by Sir Henry Torrens, in the name of the Duke of Wellington, after his Grace, as the order tells us, had actually resigned the command of the British army?

³ This is a quotation from The second Part of Henry the Sixt, with the death of the Good Duke Humfrey (London: Printed by Isaac Jaggard and Edward Blount, 1623), by William Shakespeare:

What stronger Brest-plate then a heart vntainted?
Thrice is he arm’d, that hath his Quarrell iust;
And he but naked, though lockt vp in Steele,
Whose Conscience with Iniustice is corrupted.