Workers of the world, unite!

is one of the rallying cries from The Communist Manifesto (1848)[1][2][3][4] by Karl Marx and Friedrich Engels (German: Proletarier aller Länder, vereinigt Euch!, literally 'Proletarians of all countries, unite!

[8] Five years before The Communist Manifesto, this phrase appeared in the 1843 book The Workers' Union by Flora Tristan.

The phrase was used by the Industrial Workers of the World (IWW) in their publications and songs[13][14] and was a mainstay on banners in May Day demonstrations.

[20] The guiding motto of the 2nd Comintern congress in 1920, under Lenin's directive, was "Workers and oppressed peoples of all countries, unite!".

[21] This denoted the anti-colonialist agenda of the Comintern, and was seen as an attempt to unite racially-subjugated black people and the global proletariat in anti-imperialist struggle.

The State Emblem of the Soviet Union had the slogan emblazoned on the ribbons in 15 languages spoken in the republics
The tomb of Karl Marx at Highgate Cemetery bearing the slogan "Workers of All Lands Unite"
The slogan inscribed in four languages on a wall behind the Karl Marx Monument, Chemnitz , Germany
In this still from the historical drama The Man with the Gun , the phrase (in pre-reform Russian orthography ) is depicted on a banner in the background.
Thin and small Membership card/ document of the Romanian Communist Party (PCR). Made in 1980. The party's emblem and the words "Proletari din toate țările, uniți-vă!; Carnet de membru; 1980" are on the booklet's cover.
Membership card of the Romanian Communist Party from the year 1980. The slogan "Proletari din toate țările, uniți-vă!" is written in golden letters on the top of the Pass' cover.