M1 (31.01 km (19.3 mi)) is the oldest line of the Bucharest Metro,[2] the first section having been opened on 16 November 1979.

The chosen route would run along the Dâmbovița river, from Timpuri Noi to Semănătoarea (today Petrache Poenaru), with the depot based at Ciurel.

The second section of the line opened on 28 December 1981 from Timpuri Noi to Republica, this time 10.1 kilometres (6.3 mi) long.

A few extensions followed, namely the branch line from Eroilor to Industriilor (today Preciziei) in 1983, from Semănătoarea to Crângași in 1984 and then to Gara de Nord in 1987.

[3] In 1989 the section between Gara de Nord and Dristor 2 was opened, however at the time this was considered the M3, thus completing the Crângași-Dristor branch.