The tiny seed was planted by Fr Benjamin Stolke in 1941, when he undertook to tutor a few Convent boys in Latin, thus preparing them for admission in North Point. Local students joined in. Father Stolke was soon found holding, in his own bedroom, classes of 12-15 boys ranging from Kindergarten to Matriculation and Senior Cambridge! Then, the threat of Japanese bombardment over Calcutta induced anxious parents to evacuate their children to the hills and some of them came to swell the ranks of the nascent school. Mgr. Gianora, who had long been eager to set up a high school at the headquarters of the Sikkim Mission, readily gave his blessing to the new enterprise and even consented to take up a class. The school and the Fathers were then housed in the old Prefecture Apostolic 

In 1945, it was shifted to the present presbytery. Fr. Eberhard had taken over as Principal and opened the first Admission Register with 27 entries. Foreseeing future developments Mgr. Gianora purchased 14 acres of adjacent land and leveled up a piece of building ground, but funds remained stubbornly scarce and, for another thirty years, the ‘New Land’, as it used to be called, was handed over to the Swiss Dairy. Meanwhile, an application for the school’s recognition was turned down by the Board of Secondary Education as the Government of West Bengal was itself contemplating the establishment of a Government High School in Kalimpong. We had then about sixty students, whom we naturally felt reluctant to disband. 

Fortunately, Fr. Albert Lee, who had succeeded Fr. Eberhard at the helm, calling upon all the diplomacy he was capable of, secured the good offices of Mr. Staynor, the Inspector of Anglo Indian Schools, and obtained the school's  affiliation to the University of Cambridge. Our first and lone candidate appeared in 1952. Fr. Eberhard returned from leave, but soon again handed over charge to Brother Peter Grobety, who, in two years, so enhanced the popularity of S.A.S. that it became urgent to find a solution for its extension.

By adding an aisle and a top floor Mgr. Gianora managed to contrive a very sensible increase of available space and the new dormitory could then boast of 75 economically spaced beds. The kitchen and refectory were promoted by being transferred from the present garage to the old church, no longer in use for religious purposes. Most of the classroom, however, could not hold more than 10 or 13 seats, so that, by the time the students were sieved up, the top classes were reduced at best to three or four boys. This abnormal situation was further aggravated when provisions were made for a variety of streams in the I.S.C. Exams.  To have limited ourselves to a single stream might have meant sacrificing two thirds of our total student strength, whilst the burden of maintaining at least two of them for handful of students was a financial impracticability.

There seemed to be no visible hope of any solution when suddenly, out of the blue, came a certain Swiss gentleman who was commissioned by a Swiss Government Agency dubbed SWISS TECHNICAL CO-OPERATION. Mr. Mentha’s visit at once set the wheels clicking; a detailed project was prepared; an architect and an engineer were summoned from Switzerland to discuss plans and scrutinize every little detail concerning the project. The Swiss Government grant was finally sanctioned when our Ambassador obtained ‘non-obstat’ from the Indian Ministry for External Affairs. In the autumn of 1965, the first spiteful of soil was dug up, thereby triggering of a period of hectic work that was to continue for the next five years and culminate in the beautiful campus we have just inaugurated. Such was the rush for admissions in 1967 that the first building had to be occupied before its completion and we spent the monsoon that year without a roof over our heads! This building won the admiration of Mgr. Caprio, former Internuncio who hallowed it in the month of April 1968. Meanwhile, under capable and energetic supervision of Fr. Ruckstuhl and later, Fr. Martin Rey, work was progressing steadily and in 1970, the new hostel was in turn ready to welcome the students on their return from the winter holidays. By the end of the same year, the exterior of the hall was also completed. Both hostel and hall were blessed by Mgr. H Salina, newly elected Father Abbot, in the month of November of the same year.

          The School was affiliated to the Council in the year 1970 and Fr. Edward Gressot, Fr. Thomas D’Souza, Fr. Felix Baretto, Fr. Paul D’Souza, Fr. Samuel Lepcha and Fr. Valerian Viegas have led the Institution efficiently, being its head. Fr. Lawrence Monteiro is the present Principal of the school. Fifty years after the formal inauguration of the school, the first batch of ISC appeared for their examinations of March 1995. The school had its humble beginning and it has done it's best to instill among its student the motto of the school PER ARDUA AD ASTRA -  translated literally, it means "THROUGH HARD WORK TO THE STARS". That is to say, it is by hard work and perseverance that we can succeed.