Belarus

Bate Borisov

Founded: 1973; reestablished 1996

FC BATE Borisov has won15 titles. The club has also won three Belarusian Cups and four Belarusian Super Cups. The only Belarusian club that has competed in European competition consecutively for 20 years. Since 2006 Bate Borisov won the league title for 13 years consecutively. Dinamo Minsk is the only club that comes close to BATE Borisov in getting the glory of Belarusian football, having won 7 League titles and having played European football(Europa League). BATE is the only top-flight club that has contested less than every club(22 Seasons) since it was defunct till 1996. The most prominent BATE player is Arsenal Icon Alexander Hleb. They have 3 doubles

Belgium

R.S.C Anderlecht

Founded: 1908

Royal Sporting Club Anderlecht is the most successful Belgian football team in European competitions, with five trophies, as well as in the Belgian domestic league, with 34 championship wins. They have also won 9 Belgian Cups, 3 Belgian League Cups, and 13 Belgian Supercups. They have won the European cup in 1982 and were again the finalists and runners up in the consecutive year. They were the finalists of the UEFA Cup Winners Cup for 3 consecutive years winning twice in 1976 and 1978 and also winning the UEFA super cups in these years. They have 3 doubles. They first started playing in the top tier in the 1920s and since 1936 they haven't been relegated, They have been playing Europe since 1965 and they have never finished outside the top six. In 1986, they achieved their best UEFA ranking with a joint first place with Juventus.

Bosnia and Herzegovina

FK Željezničar Sarajevo

Founded: 1921

Fudbalski klub Željezničar Sarajevo has won 6 Bosnian League Cups. They were the strong competitors for the title in Yugoslav League, during the time of the former Yugoslavia, FK Željezničar were national champions in the 1971–72 season, qualifying for the European Cup during the 1972–73. In Europe, the club is known for reaching both the UEFA Cup semi-finals during the 1984–85 season and the quarter-finals during the 1971–72 season.

Bulgaria

PFC CSKA Sofia

Founded: 1948

CSKA has won a record 31 Bulgarian titles and 20 Bulgarian Cups. Additionally, CSKA is the only Bulgarian club to have reached the semi-finals of the European Cup, which they have done twice, and they have also reached the semi-final of the UEFA Cup Winners' Cup once.

Croatia

GNK Dinamo Zagreb

Founded: 1945

Građanski nogometni klub Dinamo Zagreb is the most successful club in Croatian football, having won 20 Croatian Football League titles, 15 Croatian Football Cups, and 6 Croatian Football Super Cups. The club has spent its entire existence in the top flight, having been members of the Yugoslav First League from 1946 to 1991, and then the Croatian First League since its foundation in 1992. They have also won 9 Yugoslav First League and 8 Yugoslav Cups. Winner of Balkans Cup, winners and runners up in Inter-Cities Fairs Cup and a semi-finalist in European Cup Winners Cup. They have record 11 Domestic Doubles.