It started off with just one class - comprising sons of farmers and fishermen - in a kampung in Upper Serangoon a century ago.
But the former Montfort School, which later split into the present Montfort Junior School and Montfort Secondary School, has come a long way, producing a number of leaders in the public service and corporate arena in those 100 years.
Founded in 1916 as Holy Innocents' English School, it was renamed Montfort School in 1959 after Louis-Marie Grignion de Montfort, a Catholic saint whose efforts to educate youth are carried on by the Brothers of St Gabriel.
The Brothers arrived in Singapore in 1936 and took over the running of the school.
In 1974, the full school split into Montfort Secondary and Montfort Junior, for primary school pupils.
The Montfort schools have produced politicians, such as former Cabinet ministers Lim Boon Heng and Lee Boon Yang, and priests, including the current Archbishop of Singapore William Goh.
Some old boys have also returned to teach at their alma mater.
English teacher Edmund James, 74, has taught at Montfort Secondary for nearly 30 years and says he still feels attached to the school. "I've always wanted to come back here to teach, to bring about a positive impact in the lives of the boys."
Some students even found love at Montfort, when girls studied alongside boys in pre-university classes.
For 68-year-old Mr Ng Kok Song, former GIC chief investment officer, Montfort was where he met his wife.
For a brief period, pre-university classes for boys and girls were held in the school. These classes were introduced in 1961 with a pioneer class of 20 students, including four girls.
The classes were moved to Catholic Junior College in 1975.
Mr Ng met his late wife Patricia Chee at Montfort in his second year of pre-university education in 1966. "Patricia and her friends walked past my class that day; I looked up and I saw her. It was her cheerfulness that caught my attention."
He became head prefect that year and persuaded her to be a prefect, too, so he could get to know her better. They got married six years later.
"Looking at my life now, I realised how important my 12 years in Montfort were," he said.
In the 1980s, the area surrounding Montfort in Upper Serangoon underwent a big change: Where coconut trees once stood, housing blocks sprouted.
With student numbers expected to rise, a group ofalumni began a project to rebuild Montfort Junior and Montfort Secondary. A building fund committee was formed.
In 1991, the schools at the present Hougang site were completed, and students and staff moved to the new premises the next year.
Montfort Secondary principal Mark Gerard Minjoot said: "It is only appropriate to give thanks for the sacrifices made by the pioneers in the early years."
For the centennial celebrations, a series of events has been planned this year, including a musical, a golf tournament and a carnival. A fund- raising dinner was held earlier this month to mark the 100th anniversary of the founding of Montfort schools. Prime Minister Lee Hsien Loong, who attended the event, highlighted how the schools focused on values-driven education.
This June, the secondary school's students will participate in a Values In Action challenge to give back to the community via projects, such as a carnival for children with special needs.
Mr Minjoot said: "We hope these experiences will help each boy to be the best he can be, and to be of service to society when he leaves school."