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# Dictionary of Vexillology: J (Jack – Jolly Roger)

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Last modified: 2026-05-02 by martin karner
Keywords: vexillological terms |
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On this page:

- JACK
- JACK OF HONOUR (or HONOR)
- JACK PIN
- JACK STAFF (or JACKSTAFF)
- JACK, THE
- JAGIELLONIAN
- JAGIELLONIAN CROSS
- JAGIELLONIAN EAGLE
- JAMES UNION
- JEHOVAH-SUN
- JELLOPED (or JOWLAPPED)
- JERUSALEM CROSS
- JIGGLING JONNY
- JOINANT
- JOINED (or JOINED TOGETHER)
- JOLLY ROGER

JACK
  A flag (generally much smaller than the ensign) flown from a staff at the bow of a ship, usually when that ship is berthed, at anchor or moored to a buoy, occasionally when underway but always when dressed overall, and which in current usage may fall into one of the three main categories listed below – a bow flag (see also colonial jack, distinguishing jack, dress ship, jack of honour, jack staff, privateer jack, union jack) See supplemental note.

  Please note that, whilst the origin of this term remains disputed, it is worth recording that "jack" was a 17th century English (colloquial) diminutive, and so the smallest flag (generally) displayed by a vessel could become the "jack flag".

Civil Jack
  Flown at the bow of a merchant ship (see also civil ensign under ensign).

  Civil Jack of the Bahamas; Civil Jack of The Netherlands – unofficial

  Please note, however, there is only one country which specifically prescribes a special jack for general use by civilian vessels – the Bahamas – and one whose law permits such vessels to fly a unique flag in the bows – the UK (see pilot jack). Sweden, for example, specifies regional flags, whilst the flags of home ports are sometimes officially used and the regulations of some shipping lines call for a house or other flag with this, upon occasion, being expressly permitted under national legislation.
Government Service Jack
  Generally, but not exclusively, limited to the UK and former British colonies, and flown at the bow by civilian-manned Government vessels – but see colonial jack 1) with its following note (also government ensign under ensign and the notes below).

  Jacks of The Royal Fleet Auxiliary (ebay.co.uk), the Royal Maritime Auxiliary (flyingcolours.org) and Northern Lighthouse Board, UK

  Notes
  a) In UK usage all Government service vessels wearing defaced blue ensigns, including those used by the governing authorities of dependent territories, are legally entitled to fly a blue jack with an appropriate badge in the fly, however, (as far as can be discovered) only the Royal Fleet Auxiliary, the Royal Maritime Auxiliary and the Northern Lighthouse Board actually do so at present.
  b) In Germany and Austria, Government (as well as civilian) vessels often fly the flag of the relevant state/province, and that in some commonwealth countries the appropriate departmental flag is specified as a jack for government vessels.

Naval Jack
  Flown at the bow of a warship, often the appropriate national flag (or a variation of it), occasionally the same as the naval ensign, or sometimes a completely different design – the jack (see also masthead pennant 1), naval ensign under ensign, jack staff, suit of flags).

  Naval Jacks of Ukraine, Slovenia and Uruguay

JACK OF HONOUR (or HONOR)
  In French naval usage, a jack originally flown in place of le tricolore by ships that had served in the Free French Navy (the FNFL), and now flown by those ships bearing the same name (see also cravat 1) and its following note, fanion 3), lanyard 1), lanyard pennant, tricolour 3)).

  The FNFL Jack, France

JACK PIN
  See belaying pin.

  Jack/Belaying Pin (Wikipedia)

JACK STAFF (or JACKSTAFF)
  The short staff in the bows of a ship upon which the jack is hoisted (see also ensign staff, staff 1)).

  HMS Iron Duke 1912–1946, UK (Wikimedia); MS Basilea (1952 | swiss-ships.ch)

JACK, THE
  In UK usage and some others, an increasingly obsolete term for the naval jack – see ‘naval jack’ under jack, His Majesty’s Jack.

  The Jack/Naval Jack 1879–1946, Italy; The Jack/Naval Jack, Thailand; The Jack/Naval Jack, Norway

JAGIELLONIAN
  In East European usage a term often used to describe historic or traditional symbols, and taken from the dynasty which ruled Poland, Lithuania, Hungary, and Bohemia from the 14th century until the 16th century – as examples the Jagiellonian cross or Jagiellonian crown.

  Flag and Arms of Brzozów, Poland; Flag of Łubnice, Poland

JAGIELLONIAN CROSS
  See cross of Lorraine and jagiellonian.

  Flag and Arms of Wschowa, Poland

JAMES UNION
  An unofficial name for the 1606 pattern British union flag (see also British flag, His Majesty's jack, interlaced conjoined, union jack).

  Union Flag 1606–1801, England/UK

  Please note that this term appears to have been a 19th century invention, and that there is no firm evidence of it being used during flag’s lifetime (1606–1801).

JEHOVAH SUN
  The term – and a direct translation of the German Jehova-Sonne – which may be used to describe a sun in splendour, surmounted by a cartouche bearing the name of God in Hebrew lettering – a charge sometimes to be seen on (exclusively Protestant) German military flags of the 16th and 17th centuries (see also sun-in-splendour).

  Flag of an Infantry Company c1675, Electorate of Saxony (Klaus-Michael Schneider)

JELLOPED (or JOWLAPPED)
  The alternative heraldic terms used to describe the wattles of a domestic fowl when they of a different tincture from its body – jowlapped – but see wattle(d) 2), comb(ed) (also armed 2), attired, beaked, gorged, hardi, langued, membered).

  Flag of Lavey-Morcles, Switzerland; Flag of Šentjernej, Slovenia; Flag of Líšná, Czechia

JERUSALEM CROSS
  A symbol of the Medieval Kingdom of Jerusalem – in heraldry a cross-potent cantonée – see cross-cantonée and its following note (also cross potent and cross of Jerusalem 1)).

  Flag of the Kingdom of Jerusalem 1162–1191

JIGGLING JONNY
  See tugh 1) and its following note.

  (National Music Museum)

JOINANT
  An alternative heraldic term for conjoined.

  Arms and Flag of Marnardal, Norway

JOINED (or JOINED TOGETHER)
  In heraldry see conjoined.

  Arms and Flag of Nærøy, Norway

JOLLY ROGER
  1) Generically, any black (or occasionally red) flag often (but not invariably) bearing white symbols and associated with piracy, but usually shown in its modern form as a flag with black field and stylised white skull above two white crossed bones – a skull and cross-bones (see also privateer ensign).
  2) A flag of the latter description given above, but defaced by a number of varying symbols dependent upon the type of action and used unofficially by the submarine service of the British Royal Navy and some others to signify that the boat flying it had successfully engaged an enemy – but see battle flag 3).

  Flag as described above; Flag of Bartholomew Roberts, early 18th c.; Submarine Service, UK

  Notes
  a) With regard to 1), vessels of the US Navy often fly a Jolly Roger at the yardarm during line-crossing ceremonies (as the signal that King Neptune is aboard), however, of all known pirates only Blackbeard is thought to have actually used this design (see also yardarm).
  b) With regard to 2), it should be emphasised that these symbols were (and are) entirely unofficial, and that a several variations are known.

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