| January 29th, 1857 | Christian Brothers arrive in Mitchelstown |
| February 2nd, 1857 | School opens |
| July 4th, 1859 | Brother Anselm Sheedy arrives |
| August 15th, 1860 | Building of Monastery completed |
| November 6th, 1864 | School officially named Mount St. Bernard |
| January 16th, 1866 | First public examination in school |
| November 13th, 1868 | Death of school’s benefactor, Rev. Morgan O’ Brien |
| June 27th, 1887 | First burial, Br. Dunne, in Monastic Cemetary |
| September 9th, 1887 | The “Mitchelstown Massacre” |
| December 6th, 1904 | Br. Diarmuid O’Brien born |
| June 10th, 1907 | Death of Br. Louis Yorke |
| January 3rd, 1910 | Death of Br. Anselm Sheedy |
| August 12th,1922 | The Burning of Mitchelstown Castle |
| October 10th, 1925 | First major school extension: the gymnasium |
| June 5th, 1929 | First Leaving Certificate Class |
| August 1st, 1930 | First Lay Teacher |
| December 17th, 1930 | Electricity reaches school and Monastery |
| July 2nd, 1933 | Blessing of Galteemore Cross |
| October 7th, 1935 | First Competitive Football Game played |
| Janaury 14th, 1941 | Purchase of Football Field |
| August 31st, 1944 | Edmund Rice’s Centenary Celebrations |
| June 28th, 1950 | Opening of New Primary School |
| February 2nd, 1957 | Centenary of School |
| June 22nd, 1957 | First Football Cup won by Under 14 |
| March 30th, 1960 | First Munster Football victory by under 17 1/2 |
| March 29th, 1962 | First Oral Irish examination for Leaving Certificate |
| September 2nd, 1967 | Work begins on new school |
| September 1st, 1969 | Co-operation between Convent and C.B.S. begins |
| May 27th, 1970 | New School officially opened |
| February 12th, 1972 | First Parent Teacher Meeting |
| September 12th, 1972 | First Vice Principal, Jack Derby |
| March 14th, 1976 | Football Final defeat |
| December 12th, 1977 | Official opening of Handball alleys |
| September 5th, 1982 | School uniform introduced |
| September 14th, 1987 | Last burial, Br. Meere, in Monastic Cemetery |
| May 25th, 1992 | Board of Management established |
| August 1st, 1992 | Mr W.P. Hallihan becomes First Lay Principal |
| December 3rd, 1993 | Christian Brothers decide to withdraw from Mitchelstown |
| January 4th, 1994 | Decision to withdraw relayed to Lay Teachers |
| November 20th, 1995 | Initial application made for new school |
| May 25th, 1998 | Farewell meeting between Brothers and staff |
| April 24th, 2001 | Death of Br. Diarmuid O’ Brien |
| September 7th, 2002 | Unveiling of memorial to Br. O’ Brien in Brigown Cemetary |
| March 10th, 2004 | School wins first Munster Hurling Cup |
| March 13th, 2006 | Work begins on new school |
| April 21st, 2006 | Remains of Brothers re-interred in Brigown Cemetery |
| April 4th, 2008 | Official opening of new school |
Secondary School