Line 10. 30 June 1952: Line 13 was extended north from Porte de Saint-Ouen to Carrefour Pleyel. 27 June 1973: The line was extended south from Saint-Lazare to Miromesnil. 18 February 1975: The line was extended south from Miromesnil to Champs-Elysées – Clémenceau. 26 May 1976: The line was extended north from Carrefour Pleyel to Saint-Denis – Basilique. 9 November 1976: The line was extended from Champs-Elysées to Invalides. Line 14 was eliminated as a separate line (leaving its number available to be reused in 1998) and incorporated into Line 13. The line was extended south from Porte de Vanves to Châtillon – Montrouge. 9 May 1980: The northwestern branch of the line was extended from Porte de Clichy to Gabriel Péri. 25 May 1998: The northern branch was extended from Basilique de Saint-Denis to Saint-Denis – Université. 14 June 2008: The northwestern branch was extended from Gabriel Péri to Les Courtilles. Line B of the Nord-Sud Company On 28 December 1901, the Société du chemin de fer éléctrique souterrain Nord-Sud de Paris, or Nord-Sud Company, obtained a concession from the City of Paris to build a rapid transit network of two lines concurrent with the more prominent CMP, which had already opened the first lines of the Métro. Connecting Porte de Saint-Ouen (Paris Métro) and Saint-Lazare (Paris Métro), the construction of Line B began on 19 June 1905 with of track. Four years later, building commenced on the branch to Porte de Clichy. The line ran under Rue d'Amsterdam until its split at La Fourche, with each branch following either the Avenue de Clichy or the Avenue de Saint-Ouen. No connection was provided to the CMP. On 26 February 1911, Line B opened between Saint-Lazare and Porte de Saint-Ouen, with the northwestern branch to Porte de Clichy opening a year later. Due to the narrow width of Rue d'Amsterdam, Berlin (renamed to Liège) station was built unusually with non-aligned platforms. The Nord-Sud Company operated Line B with 368 trains per day, a minimum of 2.5-minute headways. On 1 January 1930, the CMP absorbed the Nord-Sud Company and renamed Line B to Line 13 in accordance with its numerical naming policy. The electrical supply also needed to be changed; the Nord-Sud Company used overhead power, while the CMP relied on third rail technology. In order to allow interoperability, Line 13 was switched to third rail power. Overcrowding Line 13 is