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In 1881, gymnastics club Wodan and fencing club Mars, both part of the student corps Vindicat, merged to form GSSV Donar. In 1951 the basketball department of this club was founded. In 1970 the club promoted to the highest basketball league.

In 1973 the club separated from Vindicat and got their first sponsor, Nationale-Nederlanden. This allowed the team to play in the much bigger Martinihal "Events hall". On September 20, 1980, Donar won against BOB Oud-Beijerland with a score of 158–58. The score of 158 was repeated that same season against the same team (158–82) and never since. The difference of 100 points has never been repeated.

After the first championship in 1982, Nationale Nederlanden announced to stop as sponsor. After one year of playing under their name, Donar was demoted to the rayon league. Donar became champion that year and promoted to the promotion league. In 1986, Donar returned to the highest league; where they remained ever since. On February 1, 1991, the Basketball Business Club (BBC) was founded. In 2000–01, the Martinihal was remodeled to become Martiniplaza and home games were moved to the new sports hall in the complex. This hall was renovated in 2006 when new seating was placed.

2009–2014: Successful GasTerra years

In 2009 GasTerra became the main sponsor of the club, that was renamed the GasTerra Flames. Head coach Marco van den Berg stayed and a whole new team was put together. In the 2009–10 season, Donar won the 3rd national championship in club history by beating West-Brabant Giants 4–1 in the Finals. Earlier, in the regular season, Flames finished in first place with a 33–3 record. The key players of the team were the Americans Matt Haryasz, Matt Bauscher, Jason Dourisseau and Robby Bostain.

The whole squad that won the 2010 title returned for the next season, except for Tim Blue. In 2010 they became the first Dutch basketball team to take part in the qualifying rounds of the new Euroleague. In the regular season Donar ended on the second place, while Jason Dourisseau was named the Dutch League MVP. The team won a second NBB Cup in 2011, after beating WCAA Giants The team did eventually lost in the DBL Finals to Zorg en Zekerheid Leiden 4–3 in an historic game 7 which included three overtimes.

Head coach Marco van den Berg left after the 2010–11 season and Hakim Salem, former ABC Amsterdam coach was acquired. The team brought experienced players to the team like David Bell and Alex Wesby but they couldn't meet the set expectations. In the cup competition, Flames was defeated in the quarterfinals and in the DBL semifinals it lost to EiffelTowers Den Bosch.

During the 2012–13 season Hakim Salem was fired and the Croatian coach Ivica Skelin was acquired. Despite the coaching change, team was still swept 3–0 by Zorg en Zekerheid Leiden in the DBL semifinals.

Before the 2013–14 season it was announced that GasTerra's sponsor contract ended after the season. Flames acquired Dutch top players Arvin Slagter and Ross Bekkering from defending champion ZZ Leiden and three new Americans were added to the team. On March 30, 2014, Flames won the NBB Cup by beating Zorg en Zekerheid Leiden 79–71.

In the 2014 Playoffs Flames beat BC Apollo easily in the quarterfinals (2–0) and later beat ZZ Leiden after a tough series (3–2). On June 1, 2014, Donar won its 4th national title. They beat SPM Shoeters Den Bosch 76–68 in game 7 of the Finals series.

2014–present: Donar

In the 2014 offseason, the club announced that in the previous season, a deficit of €135,000 had arisen after mistakes made regarding the budget. Therefore, the club had to cut into costs for the 2014–15 season and the budget was reduced. For the 2014–15 season, the club is known again as "Donar". The team won the Supercup against Leiden and the NBB Cup Final against Den Bosch, the DBL Finals were lost 4–1 against Den Bosch.

Braal seasons (2015–2020)

In the 2015 offseason, Ivica Skelin left the club and was replaced by Erik Braal who would go on to become the most successful coach in Donar history. In July 2015, former league MVP and club legend Jason Dourisseau returned to Donar. In the 2015–16 season, Donar won its 5th DBL title after beating Landstede 4–1 in the finals.

In the 2016–17 season, Donar reached the second round of the FIBA Europe Cup after being defeated by Tartu in the first qualification round of the Basketball Champions League. This feat would mean Donar's best European performance in club history. The 2016–17 season was also the first season ever to record the triple crown. New Heroes Den Bosch was defeated to win the Supercup, Landstede Basketbal was defeated in the NBB Cup final as well as in the playoff finals (4–1).

In the 2017–18 season, Donar qualified for the FIBA Europe Cup after being defeated in an overtime thriller against Estudiantes in the third and last qualification round of the Basketball Champions League. As a result of the loss Donar was drafted into a Europe Cup group with KK Bosna (Bosnia and Herzegovina), Le Portel (France) and Antwerp Giants (Belgium) in which they finished 2nd. By ending in second place they earned a spot in the second round phase of the Europe Cup, playingin group L against CS Universitatea Mobitelco Cluj-Napoca (Romania), Belfius Mons-Hainaut (Belgium) and Keravnos B.C. (Cyprus). After a home and away win against Cluj, a clear home win against Keravnos (109-69) and a convincing home win against Mons, Donar placed 1st in this group and, for the first time in club history, qualified itself for the Europe Cup play-off phase.

In the play-offs, Donar beat Cluj-Napoca in the round of 16 and Mornar Bar in the quarter-finals, to reach its first ever European semi-finals. In the semi-finals, Donar lost to the defending Italian champion Reyer Venezia, despite winning the second leg at home. In the 2017–18 DBL season, the club has success as well behind star players Brandyn Curry, named Most Valuable Player and All-DBL Selections Thomas Koenis and Evan Bruinsma. Donar won its third consecutive DBL title on 29 May 2018, after defeating ZZ Leiden 4–0 in the finals.

In the 2018–19 DBL season, Donar struggled and found itself in the fourth place in the regular season. It defeated ZZ Leiden in the semi-finals, 0–3. However, in the finals it lost to second-seeded Landstede. In the 2018–19 FIBA Europe Cup, Donar reached the round of 16 for the second time in history.

The 2019–20 season was cancelled prematurely in March because of the COVID-19 pandemic. Donar was supposed to play in the NBB Cup Final against Aris Leeuwarden. On 14 April, the club announced it parted ways with coach Braal.

Recent years with several head coach changes (2020–present)

On 17 April 2020, Croatian coach Ivan Rudež signed a three-year contract as head coach. On 14 April 2021, Pete Miller was assigned as head coach replacing Rudež after disappointing results. He would finish the season and, after being eliminated 2-1 in the semifinals, return to being head of Donar's youth division.

On 24 May 2021, the club announced former player Matthew Otten as the new head coach. Otten just finished his first season as head coach in the Dutch Basketball League, making it to the Cup Final with Yoast United in their first season in existence. Starting from the 2021–22 season, Donar plays in the newly formed BNXT League, in which the national leagues of Belgium and the Netherlands have merged. Despite a disappointing regular season and an early elimination in Europe and the national play-offs, Donar managed to win its 7th cup this season. Additionally, the finals of the new BNXT Playoffs were reached.

After a disappointing start of the 2022–23 season, head coach Otten was fired and replaced by his assistant Andrej Štimac on 31 October. Under Stimac, Donar was able to turn around the season and was able to reach the finals of the Dutch League for a 13th time. In the series, Donar played ZZ Leiden once again, and narrowly lost the decisive Game 5 in Leiden. In the game, Donar was up by as much as 16 points with 2 minutes and 40 seconds on the clock, before giving up the lead.

Bankruptcy

Following the end of the season, in June 2023, the board of Donar came out with a statement that revealed the club was facing serious financial difficulties. At a press conference on 29 June, Donar was revealed to have outstanding debts approximating €1.75 million. A task force was appointed with the goal of saving the club for bankruptcy, who concluded there were insufficient check and balances in the organisation, and financial troubles had been ongoing for three years but were not reported, and that called on supporters and sponsors to invest in the club. After a month of efforts to keep the club alive, the board had to file for bankruptcy due to a high demand from the tax authorities. A trustee was appointed to investigate whether a restart is possible.

The restart was initiated by a group of investors, creating a new company under the name Donar Groningen BV. In addition, a new foundation under the name Wij zijn Donar was founded, which used the money collected by supporters to purchase shares from Donar Groningen BV. Donar Groningen BV bought the contracts and the BNXT license from the trustee in order to realize the restart while keeping the club at the highest level of Dutch basketball. However, whether the club was allowed to use the same license was still to be decided by the BNXT license committee.

On the 28th of August, on the same day of the local holiday of the relief of Groningen, the new management announced that Donar Groningen BV was allowed to use the same license and play in the BNXT League in the 2023/2024 season under a few conditions. The conditions entailed that no prior board member was allowed in the new management and they received a budget cap of two thirds of their prior budget.