Saint-Michel

Early glories

Royale Union Saint-Gilloise was founded in 1897 under the matricule number 10. The club obtained its first title as champion of Belgium in 1904. A year later, they managed to win the Coupe Van der Straeten Ponthoz, which is considered one of the earliest predecessors to the UEFA Champions League.

From 1933 to 1935 the team played 60 consecutive matches undefeated, setting a still unbeaten record in Belgium, winning three league titles in a row across that period led by captain Jules Pappaert.

With its first national title barely a few years after its foundation, Union quickly became a superpower and supplier to the Belgian team for the Olympic Games in 1920.

The 1935 success was the club's eleventh, a Belgian record that would not be broken until the emergence of Anderlecht in the 1960s. Seven of those titles came before the outbreak of World War One in 1914.

Between 1958 and 1965, the club had a brief spell of European success, playing in the Inter-Cities Fairs Cup and reaching the semi-finals in the 1958–60 edition after a two-legged victory against A.S. Roma. In 1963, however, the club was relegated to the second division, and in 1980 even fell as low as the Belgian Promotion division, the fourth tier.

Lower division survival

In the sixties, Union began to struggle, bouncing between the First and Second Division several times.

In 1973, the club dropped out of the First Division and would not return for 48 years. Two years later in 1975, would come another relegation to the Third Division for the first time.

Union bounced back to the Second Division after just one season, but an even bigger decline followed at the end of the 1970s, back-to-back relegations seeing Union fall from the Second Division to the Fourth in successive years.

The club rallied in the mid-80s to earn back-to-back promotions back up to the Second Division, claiming the Fourth Division crown in 1983 and the Third the following season. But no further progress could be made and Union would move between the second and third flights for close on the next four decades.

Promotion back to the Second Division in 2004 saw two subsequent seasons of Union battling against relegation, but the 2006–07 season started brightly for Union. Promotion back to the First Division was a prospect, until a poor climax to their campaign post-Christmas, leading to the sacking of coach Tshupula Kande, replaced by Alex Czerniatynski.

In May 2007, long-standing clubchairman Enrico Bove resigned along with several other members of the board of directors, and the club suffered another relegation to the Third Division. Bove returned as chairman in 2010 with the backing of new Italian sponsors, but Union's prospects on the pitch continued to suffer.

In 2012–13, Union SG finished 17th out of 19 clubs in the Third Division B, inside the relegation zone. However, KVK Tienen were found guilty of making irregular payments and were automatically relegated to the Fourth Division, earning Union a reprieve via a play-off, which they won 1–0 against RFC de Liège.

Union went on to finish a creditable third in the 2014–15 Belgian Third Division, but again would prosper from other clubs’ problems, as the top two of Cappellen and Sprimont Comblain Sport both passed up applying for a Second Division licence, so Union were promoted in their place.

Revival and return to the First Division

On 21 May 2018, Tony Bloom, chairman of English Premier League side, Brighton & Hove Albion was confirmed as the majority shareholder. Current Union chairman Alex Muzio was a co-investor with Tony Bloom in 2018. On 7 July 2023 Alex Muzio was confirmed as having become the majority owner of Union.

Promoted from the third tier in 2015, Union quickly established themselves as a top-six side in Division 1B, without becoming a top-3 side.

A change of coach in May 2018 saw Marc Grosjean replaced after three years of finishing 6th, 4th and 6th by Luka Elsner, with Union contesting at the top of Division 1B in 2018–19, which that season was divided into South American-style "opening" and "closing" competitions, framed in the "apertura and clausura" style seen in many countries in the Americas. The winner of each competition would qualify for the promotion play-off final, with automatic promotion being the incentive for a club to try to win both competitions.

Union were second behind Mechelen by six points in the Opening Tournament which concluded at Christmas, and regrouped to take third behind Beerschot Wilrijk in the Closing Tournament. Despite not reaching the final, Union's reward was to be given one of the three places allocated for Division 1B teams in Play-Offs 2, for the right to compete for a place in the UEFA Europa League.

Placed in a group of six with every other opponent being from the top division, USG went unbeaten at home, beating Kortrijk, Waasland-Beveren and Cercle Brugge, drawing with Zulte Waregem and Excel Mouscron. Away wins over Kortrijk, Mouscron and Cercle put them in with a big chance of winning the group to qualify for the Play-Offs 2 Final, but losses away to Waasland-Beveren and Zulte Waregem saw them overtaken by Kortrijk right at the end. The Kerels finished on 24 points, Union 20.