May Day marks the worldwide celebration of International Workers' Day, or Labour Day. The date was chosen to commemorate the Haymarket riot, which took place in Chicago on 4 May 1886; it was formally recognised as an annual event at the Second International's second congress in 1891. In Greece, the first Labour Day demonstration was held in 1893, in Athens, at the initiative of the Central Socialist Society of Stavros Kallergis.
Stavros Kallergis was one of the socialist movement’s pioneers in Greece; he had founded the Central Socialist Society in 1890 and, in the same year, had launched the newspaper Socialist. In 1891, along with a few of his close companions, he took a symbolic photograph to commemorate Workers’ Day, while the next year he organised a rather small gathering of protesters.
On 1893, the Central Socialist Society called on workers to have a massive demonstration at the Panathenaic Stadium, in the centre of Athens. May 1st fell on a Saturday -then a working day- so Sunday 2 May was chosen instead. Writing about that first worker’s gathering, the Socialist put the crowd at 2,000, while other sources provided lower estimates.