1983 – Established the school
1983 - School started in Poomkavu Parish Hall with 131 students in the 8th standard on June 15th.
1984 – Foundation stone laid for the new building by the cochin Bishop Rt. Rev. Fr. Joseph Kureethara on May 10th.
1985 – The school shifted from Parish Hall to the new building on July 6th
1986 - First batch appeared for SSLC Examination and 35 students passed out of 36 students appeared.
1987 – Selected as the best school in Mararikkulam South Gramapanchayat. SSLC win percent was 94
1988 – An open stage was built with help of public, 95% was the win percentage in SSLC.
1989 – Started Scouts and Guides troups in the school. And won the overall championship in Alappuzha District School Science Fair.
1990 – Started the construction of school auditorium won the championship in Alappuzha District School Science Fair. Selected as the best school in the kerala state science fair.
1991 – Entered the information technology age with the commencement of computer classes. Also came first in the District Science Fair. Also got a clear leadership in extra carricular activities by hosting the Panchayath level basketball tournament in the school and also won the championship.
1992 – Repeated the history again in the State Science Fair by winning the championship and increased the SSLC winning percentage to 94%.
1993 – Celebrated the Centenary of Bishop L.R. Morrow and The school band troup was inaugurated by Rt. Rev. Fr. Joseph Kureethara. Secured chaimpionship in District Maths and Science Fair. The Mathematics Faculty Sri.P.G. Unnikrishnan secured the first place in teaching aid competition.
1994 – The tenth year celebration was inaugurated by Sri. Oommen Chandy. The function was preceeded by Rt. Rev. Fr. Joseph Kureethara. School band troup secured A grade in State Youth Festival. And the success rate in SSLC examination was 96%.
1995 – The environment protection award from ‘Kerala Shastra Sahithya Parishath’ was awarded to the School. Retained the No. 1 Position in District Science Fair and secured the first place in Drama, Lite Music and Band in Sub Distric Youth Festival. And the Band Troup secured first place in District Youth Festival and A grade in State Youth Festival. And also selected as the best school in state Science Fair for the consecutive third year. Success rate in SSLC Examination was 95%.
1996 – Secured the first place in District Maths and Science Fair. Succes Rate in SSLC was 94%.
1997 – The Band Troup Secured First place in District Youth Festival for the Band Display and secured A grade iin State Youth Festival.
1998 – The team from MIHS bagged second prize in Zonal basketball tournament. Success Rate in SSLC Examination was 96%.
1999 – The school team secured first place in District Sports Meet. The sub-district youth festival was hosted by the school. After a long period of service the headmistress Sr.Elsa Varappadavil retired and Sr. Benita took charge as Headmistress. Success rate in SSLC was 90%.
2000 – Again bagged the championship in District Science Fair.
2001 – Sr.Mercy Joseph took Charge as the headmistress after the retirement of Sr. Benita. Teaching faculty Krishnakumaridevi also retired in the same year. The new Computer Lab started functioning. Success rate in SSLC Examination was 89%.
2002 – Secured the first place in District Science Fair. The new school building inaugurated on August 8. Succes Rate in SSLC was 94%.
2003 – School secured special prize in ‘Vijnhanolsavam’ conducted by Kerala Shastra Sahitya Parishath. Succes Rate in SSLC was 94%.
2004 – Secured First place in District Science Fair and Bagged Second Place in Stat Scienc Fair. Success rate in SSLC was 85%.
2005 – Secured First place in District Science Fair and District Maths Fair. The Students Collected Rs 13,705 for the Health Care Charitable Society. The Success rate in SSLC Examination was 82%.
2006 – The School hosted Alleppey District ‘Prathibha Sangamam’. Renovated basketball court was inaugurated. Secured First Place in District Science Fair and secured Second prize in Maths Fair. And also secured first prize in Still Model. Success rate in SSLC Examination was 85%.
2007 – Sr. Lissy Ignasious took charge as Head Mistress from Sr.Mercy Joseph. Bagged First Prize in Lite Music and Second Prize in Classical Music in Sub-District Youth Fetival. Again Secured First Place in both District Science Fair and Maths Fair. Non teching staff Mrs.Thressiamma.M was retired. Success rate in SSLC Examination was 94%.
2008 – Vargheese Sebastian became the first student from the school to secure a first prize with A Grade in State Level Youth Festival in Lite Music Category. And the band troup complimented the succes with an A grade in State Level.
2009 - MIHS celebrated its Silver Jubilee . Celebrations last for 1 year. The alumni association of MIHS (MIOSA ) revamped as part of the celebrations. School PTA selected as the best aided school PTA in the Kerala state. MIOSA build a home for one of the poorest students in the school as the souvanir of Silver Jubilee of the school. The SSLC winning percentage is 99 in 2009. School won state level prizes in State School Science Fair/ Maths fair and IT fair
School came up with 100 % success in SSLC. 7 students secured A+ scores in all subjects.