Borussia Dortmund (BVB) is a German professional football club headquartered in Dortmund, North Rhine-Westphalia. Founded in 1909 by eighteen football players, the club is renowned for its men's team, which plays in the Bundesliga, the top tier of German football. Nicknamed Die Schwarzgelben (The Black and Yellow) for their club colors, BVB holds a fierce rivalry with Schalke 04 (Revierderby) and Bayern Munich (Der Klassiker). With approximately 218,000 members, it is Germany's largest sports club by membership after FC Bayern Munich. The club plays its home matches at the Westfalenstadion, Germany's largest stadium, featuring the iconic Yellow Wall standing terrace. BVB has won eight Bundesliga titles, five DFB-Pokals, and six DFL-Supercups domestically, plus the UEFA Champions League (1997), European Cup Winners' Cup (1966), and Intercontinental Cup (1997). Under manager Ottmar Hitzfeld, the club won back-to-back Bundesliga titles (1995-96) and the Champions League in 1997. The club became publicly traded in 2000 and has faced financial challenges, including a near-bankruptcy in 2005, which led to stadium renaming (Signal Iduna Park) and player wage cuts. BVB's youth system, developed under Michael Zorc, has produced stars like Matthias Sammer and Robert Lewandowski. The club's fan culture is highly politicized, with progressive ultras promoting anti-racism while facing challenges from far-right factions. BVB's training facilities include the Hohenbuschei complex and Footbonaut robot. The club's kit is sponsored by Vodafone and Puma, with sleeve sponsorship from Opel. Controversies include a 2023 sponsorship deal with Rheinmetall, criticized as 'sportswashing'.