E.g. Lajos Kiss suggests the Turkish origin,[1] whilst Slovak scholars have been suggesting the Slavic origin since the times of Ján Stanislav[2] who accepted Moór's theory as more reliable and pointed to several place names with similar etymology (*Bor[I]ša).

The castle – which stood near modern-day Edelény – bore the name of its first steward, Bors, who lived during the reigns of either High Prince Géza or his son Stephen I.

This is also evident from place names like Szirmabesenyő (besenyő is the Hungarian word for Pecheneg) and Ózd (from "úz").

The Battle of Mohi – marking the beginning of the Mongol invasion which had a disastrous effect on Hungary – took place in Borsod county, near the village of Muhi, on 11 April 1241.

Before the battle of Mohács (1526), which marks the beginning of the Ottoman occupation of Hungary (lasting for over 160 years) the county had 13 castles, 13 market towns (oppidum, including Miskolc and Mezőkövesd) and 250 villages, owned by 235 different feudal lords including dioceses and monasteries.

There were some minor changes in the area of the county during the 19th century: between 1807 and 1812 the villages Szőlőske, Cegléd, Tihamér, Almagyar, Felnémet and Bekölce (many of these are today city parts of Eger) were annexed to the neighbouring Heves county, while Egerfarmos, Ivánka, Szőkepuszta and the mill of Kistálya were annexed from Heves to Borsod.

In 1850 several other towns and villages of Borsod were annexed to neighbouring counties: Andornak, Kistálya and Felsőtárkány to Heves, Domaháza and Sikátor to Gömör and Kishont.

In 1907, Miskolc was granted the rank of city with municipal rights, becoming de jure independent from Borsod county.

On 2 November 1938, the First Vienna Award returned to Hungary some parts of Gömör and Kishont lost in 1920; Borsod and Gömör-Kishont became independent from each other again but the border between them slightly changed.

After World War II, the Vienna Award was declared void and Hungary lost the northern territories to Czechoslovakia again; in 1945, the 1938 law was repealed and the remaining part of Gömör-Kishont was merged with Borsod county again, forming Borsod-Gömör county.