Idrottsföreningen Kamraterna Norrköping, more commonly known as IFK Norrköping or simply Norrköping, is a Swedish professional football club based in Norrköping. The club is affiliated to Östergötlands Fotbollförbund and play their home games at Östgötaporten. The club colours, reflected in their crest and kit, are blue and white. Formed on 29 May 1897, the club have won thirteen national championship titles and six national cup titles. The club is currently playing in Allsvenskan, where the season lasts from April to October. The club first won Allsvenskan in 1943. IFK Norrköping were most successful during the 1940s, when they won five Swedish championships and two Svenska Cupen titles under the Hungarian coach Lajos Czeizler and with players like Gunnar Nordahl and Nils Liedholm. IFK Norrköping won the 2015 Allsvenskan, their first win since 1989, which also gave them a spot in the second qualification round of 2016–17 UEFA Champions League.