During the centuries, Turkish authorities had made a sleepy small town of Banjaluka, settled on 19-th century with only ten thousand souls: little merchants, traditional craftsman, clerks, soldiers, various priests, a few teachers, and their families. Only Austria-Hungary occupation of Bosnia and Herzegovina in 1878 finally has brought achievements and spirit of Europe in our regions, in almost all fields of life, and in schooling too. Although it had not provided the entirely national-religious equality the Habsburgs rule meant greater law confidence, economic prosperity and not negligible cultural progress. Banja Luka as new administrative, military and mercantile  environment, gradually had changed its sleepy oriental physiognomy and had got contour of modern town. Even though slow, Europeanization had seen on every step, starting with costume, nutrition, dwelling, through appearance of new handicrafts and inception of modern industry and transportation up to foundation of contemporary cultural and educational societies and institutions.

One of such institutions was Big Real established on October 10, 1895 with mission to prepare students" for foresters, for agricultural, chemical and others high-schools".

Teaching in the first years had been maintained in former Ruzdija (Turkish Islamic middle school), and on Mart 01, 1898 year The Real had moved in new two-floor building which in its "splendid manufacture" and "perfection [...] of architectonic skill" satisfied "all whishes of strict pedagogy demands". And a lot more: The building of Gymnasium, which many had named "Bastilja", is going to became proud and one of omens of Banja Luka. 

    The Big Real in the beginning had been reserved for boys only, and girls hadn't right to attend it until 1912, first as extraordinary, and after 1919 as regular students.

Eight-class teaching went threw 15 subjects, and according to plan and curriculum of Hapsburg authorities. Number of pupils in this period had almost regular growth, and from the first 66 it raised at 430 (1917/18). The first 12 students graduated on 1903.

The first generations mostly studied mathematics, drawing and geometry. The school gradually grew from Big Real into Real High-school which emphasized languages (Serbian, Germany, France) and history, having installed 16th subject - Latin language too. Marks were from one (the best) to four (insufficient).

Attending High-school had meant respecting severe orders: students must wear pupils cap with classroom number (the best had additional marks on the caps), students going out were limited until 7 or 8 PM, and so on.

Except it had priority over pedagogy, the High-school early became cultural, science, and national institution. Until the First World War in Gymnasium had been founded a vocal group, tamburitza orchestra, players of a stringed instrument and various pupils societies, including illegal political organizations.

    The Annexation crisis (1908-1909) and Balkan wars (1912-1913) rolled student and teachers spirits, but also increased suspicions of Wiena authorities, that turned into almost anti-Serbian discrimination. In beginning, it had been mobilized a few teachers and about thirty students, than came prohibitions of students associations and Cyrillic, followed by series of court trials against followers of Yugoslav unifiers. The hunt culminated with famous Banjaluka high treason process in 1915-16 year. The autumn 1918 brought the end of Austro-Hungarian ruling that lasted 40 years, and opened a new page in Gymnasium history.

Creating Kingdom of Serbs, Croats and Slovenians in 1918 year, the Banjaluka Gimnazija found itself in essentially different conditions. War destructions, sufferings, poverty, unification of teaching curriculum, lack of teachers and many other circumstances put the school to the front of series of problems and temptations. Changes were heavy and frequent.

The Liberation found six classrooms of Real Gymnasium in their school benches and two classes (seventh and eight) of the Real.

Immediately after the liberation Cyrillic was returned, and later on the first after-wars school year it is allowed  to the pupils to be a full-time students. From 1920, after third class, it was carried out bifurcation (fork) in two directions: gymnasium-humanistic (learning Greece too) and real-Gymnasium. Three years later, it was introduced so-called small graduate, as selective examination, which was passed after the fourth class. From 1925 year, it had been applied a new way of grade pupils: excellent (5), very good (4), good (3), sufficient (2) and not-sufficient (1), in addition that a Law from 1929, the last two marks, changed into failing (2) and bad (1), treating them as impassable. From 1927 year the pupils had school booklets, which is used as identity card out of school too.

Although the Law from 1929 finally regulated work in Yugoslav middle schools and verified many changes, and in the next years too, all to the Second WW, it had happened permanent innovations and changes. So, in 1935 year it had been led into entrance examination on Srpski language and mathematics. The same year was founded Girls Gymnasium, which is overgrown into Full Girls Gymnasium. According to happenings in Europe and changes in Yugoslav foreign policy, from 1937 students of the Gymnasium obtained possibility to learn English instead of  German, and from 1939 Italian language too.

Meanwhile it happened a significant increase of students. So, on school year 1933/34 the number of pupils was 836.

The second world war brought even more sufferings than the earlier. Bosnia and Herzegovina entered into NDH (Independent State Croatia), whose capital should been Banja Luka. Ustasha, that is Croatian clergy-fascistic authorities, ordered to all teachers, and to the Gymnasium too, to take an oath to head of Croatia Ante Pavelic. Genocide against-Serbia politics forced some Gymnasium teachers to escape into Serbia, and most of former students and pupils of that time, and some of the teachers, replaced their classroom and chalks with wood and guns.

     On beginning of the first war school-year in Gymnasium building had immigrated Teachers school and a business academy. So, in the same building there were reduced number of teachers and pupils from four Banjaluka schools. But not for long, because already at the end of 1942 year Germans had transformed the building of the secondary school into barracks and warehouse, and expelled pupil boys went to Mekteb (Muslim  primary school) and to firefighting house, and girls to area of Medrese (Muslim secondary school). Because of shortage of the classrooms, pupils went to lessons only three day per week. In autumn 1944, because of the next reduce of the pupils and teachers, Men and Women Gymnasium become united again. Except, on September 1944 allied airplanes aiming to Ustasha base in Kastel, hit the "Bastilja" and destroyed roof and the physics cabinet. In such conditions Gymnasium welcomed liberation of Banja Luka on April 22, 1945.

In already twenty day after the liberation, on May 11, 1945 Gymnasium opened its door to the pupils again. But, just finished four-years cataclysm and radical political and ideological changes asked much effort and means for normalization of teaching. After all, it needed to reclaim severe damaged old building of the Real, so the improvised lectures were organized in former building of Civil school. On November of the same year, that, until then Mixed gymnasium, had been divided into Male and Female, as soon as, after the liberation, had been announced changes and reforms that were going to sign all after-war period. At the same time, for the incomplete Gymnasium pupils, which had been expelled from the classrooms during the war, was formed, so called "Partisan gymnasium" made of accelerated courses in order to these expelled "catch a connection" with the persons of the same age. In keeping with political and ideological changes, religious instructions and German language were pushed out from the teaching, and new subjects were introduced, such as Russian language, and it in all eight years, then preconscription training, and a few years later a moral education too.

In Autumn 1947 was finished a reconstruction of the "Bastilja" were immigrated pupils of Male and Female gymnasium, School for common education of workers (so called "Evening school"), Course for military officers, and from Autumn 1949 when had begun Lower mixed gymnasium, which in next school year was moved into building of tax administration.

Nevertheless, with start of 50th years the conditions arranged. Number of all students in Male and Female gymnasium dropped at about 1300. On year 1945 two mixed gymnasiums had been made and than, they were transformed into the Real gymnasium and eight-year primary school in the next year. So, Banjaluka Gymnasium, in its organization, finally become modern four-years middle school in which arrive pupils after complete eight-years primary school.

About ten years after the war, student workshops had been taken into (electrician's, locksmith's, tailor's, carpenter's), debating and Esperanto club, and Marks group.

Small final examination existed until 1952, and the Big was in 1959 transformed into final examination with the graduate work, to which in 1962 was added an examination of Serbo-Croatian language.

In the whole country 60's announced a era of prosperity, happiness and common progress. But such things didn't happened in Banja Luka, this time because of nature. Namely, on Sunday, on October 26th, 1969 destructive earthquake, intensity of 7.5 degrees by Mercally,  hit  this region. The good in that misfortune had been the order not to participate the lessons, and the second earthquake happened next morning. That stroke had intensity of 8.5 degrees in Mercally. Although the small number of victims (19), material destruction were enormous. Element leveled city to the ground, or made irreparable damage of many economy structures, public and private buildings, houses, roads, bridges, etc. One of that buildings was the pride of Banja Luka, popular 71 aged "Bastilja". The building was "on legs", but hardly damaged, so it was teared down.

    Meanwhile, the whole Yugoslavia and good part of the world rushed to aid. Almost the whole Gymnasium, most of the pupils (near thousand), including teachers and rest of the staff, were evacuated into Crikvenica, Novi Vinodolski and Selce, where the school-year was continued.

   Having had finished a little shorter school-year, followed touching return into not-renovated the "Capital of Krajina". Next school-year began in school-yards and huts of primary school "Braća Pavlić" (today's "Ivo Andrić"), Technical school, and partly in rooms of "Radnički univerzitet" (Workers school), and from December 1970 in new, unfinished primary school in Borik.

    Meanwhile, remnants of the old Real, with tears and unbeliever of many Banja Luka citizens, had been mined, and as an aid from Sarajevo, on the place of former Medical school in the street Zmaj Jovina emerged new modern structure made by red brick. Building with 17 classrooms, assembly hall, reading room, library, physical training hall, and other rooms had been finished at the end of 1971, and formally opened on January 15th, 1972. However, loss of the old magnificent building, that was trademark of Gymnasium, and founding of Teacher's collage, higher schools, and finally University (1975), held back Gymnasium from the first significant place in the town. But, it remained elite middle school, from whose benches recruited the best students of many high school institutions. And Gymnasium, in that lethargic time, nevertheless, had aureole of the old glory mostly because of enthusiasts between teachers and pupils. Namely, in 70's of the 20th century in the Gymnasium worked many successful companies and sections, as newspaper Orfej (started 1965), Chorus (1971), Literal-debate club, Stage club (1972), Atelier (1978), and Musical-Vocal ensemble Glasovi Kraine (Voices of Kraina/frontier area) (1978), that performed usual and high-grade programs, attractive to the non-gymnasium audience too. Because of the earthquake, instead of 75th anniversary, at 1975 maintained 80th anniversary, when was issued large monograph Banjaluka Real penned by famous teacher and former principal Mato Dzaja.

And then happened 80' and one more cataclysm.  In contrast to former misfortune, this didn't take off human lives and had not direct material damage, but its consequences to Gymnasium had been almost equally tragic. It is talking about famous "revenge of the pupil who are repeating a grade", that is about Yugoslav secondary-school reform which involved so cold "specialized training". Experiment ordered common plan and curriculum for the first and second classrooms in all schools, and after that a specialization to specific profession. That mechanically leveling hit especially a gymnasium, as an elite secondary school. That come with ugly name "School for education cadre in field of culture and art". Reform had very negative consequences: many of the teachers become surplus manpower, and suddenly dropped interest to enroll pupils in the school, so it overcome by apathy, Things changed to better from 1985, when the old name Gymnasium was turned back, when, simultaneously the number of pupils grow. Although with the curriculum for specialized training, it turned out that Gymnasia offered the best base for further education. Finally, at the end of 1990, the Law of Special Secondary Education was canceled, and township parliament of Banja Luka on May 8th, 1991 established the school (again).

Soon, one more war had broken out, leading a new plague. Many non-Serbian teachers and pupils left Gymnasia and Banja Luka, and from the other side, refugees from Croatia and other part of Bosnia and Herzegovina flow into. Besides, the war and psychosis of war, brought many other troubles: deficit of power and heating, shift of the school semesters toward summer months, shortage of school-books and teaching aids, situations often traumatically, poverty and fight for survival.

Meanwhile, at 1993 the new common plan and curriculum for Gymnasiums in Republic of Serbs has passed, anticipating three programs: common, society-lingual, and natural-math.

Dayton peace agreement at 1995 finished the war in Bosnia, but many problems, first of all material, has lasted. The peace, by the time, brought normalization of the teaching process, so Gymnasia in year 2001 has more than 1200 pupils, and more than hundred teachers, librarians, clerks and others.