Megye (county) in northeastern Hungary until 1918, extending northwestwards from the River Tisza. Its capital was Miskolc. It lay in Royal Hungary, the Habsburg-ruled part, from 1526, but was one of the counties temporarily detached to Transylvania in the 1620s and for longer from 1645 until 1687.
In 1920 the north of the county became part of Czechoslovakia while Borsod was joined with the remnant of another county, which had lost even more of its territory, to form Borsod-Gömör-Kishont. In 1938 Hungary recovered part of its Slovak lands, to lose them again in 1945. In 1949 the number of counties was reduced and three inter-war counties were joined to form Borsod-Arbaúj-Zemplén, all of which had lost lands to the Slovak part of Czechoslovakia. Miskolc remains the capital.