Polonia Warszawa

The double came in the 1999/2000 season, when Jerzy Engel took Polonia to the Ekstraklasa title and the Puchar Polski in the same year, with Piotr Reiss finishing as the league's top scorer on 21 goals. The Superpuchar Polski followed that year against Amica Wronki, and the Puchar Ligi came with a final win over Legia Warszawa. It was the club's second championship, the first having arrived in 1946, when Polonia took the title amid the ruins of a capital still recovering from the war. A cup had come earlier still, in 1952, won from the Second League against Legia.

The club traces itself to 19 November 1911, when it lost its first match 3-4 against Korona Warszawa; formal registration as KS Polonia followed in 1915, granted under German occupying authority during the First World War. Between the wars it stood among Poland's strongest sides, finishing runners-up in 1921. The club's first president, Tadeusz Gebethner, who had also captained the side, was killed in a concentration camp during the Second World War; two other prewar players, Adam Kogut and Julian Niemczycki, died at Katyn.

Relegation arrived in the mid-2000s, and Polonia bought its way back to the top flight in 2007/2008 by purchasing a licence from Dyskobolia Grodzisk Wielkopolski. The following recovery did not hold: by 2012/2013 the club was refused a licence for the season ahead and effectively ceased to exist as a company. It restarted in the fourth tier in 2013/2014, then worked its way back up, winning the third division in 2021/2022 and the second in 2022/2023 before returning to the second-tier I liga in 2023/2024.

Polonia plays in black shirts, white shorts and red socks, taken from the Polish flag, which earned it the nickname Black Shirts. Home matches are played at the Stadion Polonii Warszawa im. gen. Kazimierza Sosnkowskiego, known locally as K6, holding 7,150. Matches against Legia Warszawa, the Derby Warszawy, remain the fixture that matters most, though Polonia has not stood level with its rival at the top of Polish football since that season under Engel.