Starting from the Neolithic age the town was continuously inhabited. The emerging high grounds were homes for various people - Kimmers, Celts, Vandals, Slavic – for thousand years. But from the end of the 9th century Hungarians are living in the territory.
After the establishment of the Hungarian Kingdom the settlement and the whole Bodrogköz (Medzibodrožie) became the part of Zemplén (Zemplín) county. We meet with the name of the community “Helmech” in the endowment of Lelesz (Leles) dated in 1214. At the beginning of the 14th century the papal tax-collectors found a developed settlement and a stone church here; the Gothic ancestor of the present Roman Catholic church. From the middle of the 15th century Királyhelmec (Kráľovský Chlmec) got a market – town status, which is verified by its coat of arm and signet referring to wine culture.
At the beginning of the 16th century Péter Perényi built a fortified castle above the town on the high ground. Today the ruins of this castle are known as the Csonkavár. In the 17th century our town temporarily belonged under the principality of Transylvania. During that time Zsuzsanna Lorántffy, who was the widow of György Rákóczi I, ordered a mansion to be built here.
In the second half of the 19th century the achievement of middle class status of our town started to accelerate when the settlement became the seat of the district court. During these years and at the first half of the 20th century the present Main Street and some eclectic buildings: the hospital, the head office and the official residence of the water conservancy. These buildings are all connected with the name of count Mailáth.
Between 1930-1944 László Mécs the Premonstrant cleric poet was living and writing in Királyhelmec (Kráľovský Chlmec).
In 1920 the settlement together with the Upper – Bodrogköz (Medzibodrožie) was attached to Czechoslovakia.
The town inhabited mainly by Hungarians became the seat of Bodrogköz (Medzibodrožie) district court until 1960. After this the seat of the district court became Tőketerebes (Trebišov) but the change had an unfavourable effect on the town and region. The development slowed down in all aspects or rather started to stagnate. After the democratic transformation in 1989 Királyhelmec (Kráľovský Chlmec) far from the centres is cooperating with home and foreign partners continuously trying to break through from the isolation.