The Ekstraklasa, current styled as the Orange Ekstraklasa for sponsorship purposes, is the top division of Polish football premier league.  The Ekstraklasa (former I liga) was formed as Liga Piłki Nożnej (LPN) on 1 March 1927 in Warsaw, but Polish Championships as non-league competition and The Polish Football Federation PZPN (Polski Związek Piłki Nożnej) had been organized on 20 December 1919 in Warsaw, a year after the independence of Poland in 1918. First, historic games of the freshly created League took place on April 3, 1927 (for more information about games in the 1920s and 1930s, see Polish Football League 1927-1939)

Currently the Ekstraklasa has 16 teams. The winner automatically receives the Polish Championship title. In the course of the time, number of teams participating in the Ekstraklasa games differed. In the 1990s there were as many as 18 teams, but in late 1930s - only 10.  Several clubs have been involved in a corruption scandal and were/are in danger of relegation:

Arka Gdynia - relegated from 1st to 2nd division, -5 points at the start of next season
Górnik Łęczna - relegated from 1st to 3rd division, -6 points at the start of next season
Górnik Polkowice - 70 000 zł penalty, relegated from 2nd to 4th division, -6 points at the start of next season
KSZO Ostrowiec Świętokrzyski - relegated from 2nd to 3rd division, - 6 points at the start of the next season
Zagłębie Sosnowiec - at the end of 2007/08 will be relegated one level lower, so if they'll end the season as 16th or 15th team of 1st division, they'll be relegated to 3rd division, if they finish the league at a higher place, they'll be relegated to 2nd division
Widzew Łódź - at the end of 2007/08 will be relegated one level lower due to corruption.
Other clubs which are partly involved in corruption scandal:

Korona Kielce (1st division)
Zagłębie Lubin(1st division) Polish champion 2006-2007

Click on the left hand menu for details of some of the venues below

Odra Wodzisław Wodzisław Śląski 10th MOSiR Stadium; 6,700  Janusz Białek 

Piast Gliwice - Gliwice - Stadion Piast - Capacity: 5,000. Promoted due to scandal

Jagiellonia Białystok - Białystok - Hetman Stadium; 7,500  Capacity 

Polonia Bytom - Bytom - Stadion imienia Edwarda Szymkowiaka; 10,000 (2 500 seats)

- Bełchatów - GKS Stadium; 6 870 Capacity

Zagłębie Lubin - Lubin - Stadion GOS -15,000 (7 300 seats) Capacity

Ruch Chorzów - Chorzów - Ruch Stadium; 10,000  Capacity.  For more details on football in Chorzow click here.

Lechia Gdansk - Gdansk - Stadion Lechii - Capacity: 20,000.For more details on football in Gdansk click here.  

Arka Gdynia - Gdynia - Stadion GOSiR.  Capacity: 12,000.  For more details on football in Gdansk click here.

Wisła Kraków - Kraków -Wisła Stadium; 20,346 Capacity. Champions again last season.  The stadium is being redeveloped as part of the 2012 bid.  More details can be found here.

Cracovia Krakow - Krakow - Marshal Jozef Pilsudski Stadium
Capacity: 15,100 All seater.  Located on the south side of the main park in Krakow, just a kilometre from the Wisla stadium.  More details can be found here.

Łódzki Klub Sportowy - Łódź - ŁKS Stadium; 15,000 (12 160 seats). More details on football in Łódź can be found here.

Widzew Łódź - Łódź - Widzew Stadium; 9,892  Capacity.  More details on football in Łódź can be found here.

Polonia Warsaw - Warsaw - Stadion Polonii - Capacity 6,200. Promoted due to scandal. More details on football in Warsaw can be found here.

Lech Poznań -  Poznań - Stadion Miejski; 24,166 Capacity.  One of the best designed grounds in Europe.  Will be one of the venues used in Euro2012.  For more details click here.

Legia Warszawa - Warsaw - Stadion Wojska Polskiego - 15,378 (13 622 seats).  More details on football in Warsaw can be found here.

Slask Wroclaw - Wroclaw - Stadion Slaska - Capacity: 13,000

Górnik Zabrze - Zabrze - Stadion imienia Ernesta Pohla; 17,000 Capacity.  Located in the Chorzow conurbation.

Relegated as of the end of 2007/08

Korona Kielce - Kielce - Stadion Miejski Kielce -15,500 Capacity.  Relegated at the end of 2007/08 although due to the match fixing scandal may give them a reprieve.

For a complete overview of football in Poland go to Footiemap.com's excellent site.