Found in excavated condition, published with results of c-14 and XRF analysis.

72 cm / 30.3 inch
54.5 cm / 16.3 inch
forte 6.5 mm
middle 4 mm
near tip 2.5 mm
forte 39 mm
567 grams
Presented in this article is a somewhat rare example of a purely practical Vietnamese fighting saber, engraved with initials and a date: 1887. This is the year that the French completely conquered Vietnam and founded French Indochina.
Practical fighting guom
The sword is rather handy in the hand and the relatively short blade would have helped its use in dense jungle or urban environments. You can see it has been used, numerous cuts from other edged weapons are visible on both sides of the blade. It is engraved with the typical floral motifs found on Vietnamese weapons, but incorporated in these engravings are what appear to be the letters "C.J" on the left side and the year 1887 on the other side.
The handle is comprised of a simple piece of hardwood with a pommel consisting of a cap of horn. The iron ferrule is quite nicely made for such a simple, practical piece with some attention to the detail of its geometry. The simple iron guard is bent in the middle, perhaps by being hit repeatedly. As is common on Vietnamese swords, it has washers known as "seppa" from Japanese swords, an influence of Japanese presence in the area.
Historical background
Vietnam of the 19th century was the stage of various wars, many with the French colonists. When the Taiping rebellion was crushed by the Qing army in 1864, one of its self-proclaimed princes, Liu Yongfu, fled into Upper Tonkin part of the Empire of Annam (present-day Vietnam) with his Black Flag Army. There, backed up by the regular army of Annam they fought the French, which escalated into the Sino-French War of 1884 - 1885. The Black Flags officially disbanded in 1885 although its former members continued to harass the French in the region. In 1886 the French started the long Pacification of Tonkin which lasted until 1896. In 1887, the year we see on the blade, French Indochina was founded.
This sword, which turned up in France, is probably used during these conflicts. A battle trophy after the Sino-French war is the most straightforward explanation, with markings added at the end of a war. Although, it is a bit puzzling that the decoration seems to be done at the same time as the markings, giving rise to the idea that it might have been made with the initials and date, and then used in battle. The French military were not the only European men-at-arms active in the region. It is known that under the Black Flags were many soldiers of fortune who fought for the Taiping, and later the Black Flag's cause. It is conceivable that the sword belonged to one of those fighters, who perhaps returned home with it after the disbanding of his army.
The hilt is in the typical Marwari Rajput style, made by Ram Namar in 1857 A.D.
An exceedingly rare set with fine mother of pearl inlaid string board