Old Boys from far and wide gathered together for the celebration. The event started with fireworks at the upper field of the DMGS field. After a courtesy visit to the Obi of Onitsha Igwe Nnaemeka Alfred Achebe on Saturday 25th January, the Old Boys, students and friends of DMGS, gathered together at the All Saints Cathedral Onitsha for the Centenary Service.

In his sermon the Bishop eulogised members of the DMGS Old Boys Association (DOBA) and encouraged them to continue working together with the Diocese, to ensure that the school is taken to greater heights. He informed the Old Boys that although he is not an Old Boy of the school, that he has contued to champion the motto of the school and advertise the school more than anyone else.

After the Church service at the Cathedral, the Bishop, The Rt. Rev Dr Owen C. Nwokolo, Bishop on the Niger, laid the foundation stone of three buildings – the New Centenary Building, the Tower and The Obijackson Indoor Sports Arena. After the foundation stone laying event, the DOBA World Wide President Dr Sunny Nwachukwu and a Trustee of the DMGS Old Boys Association, and former minister of Health Dr Tim Menakaya in the presence of all those present honoured the Bishop as an Honorary Member of the DMGS Old Boys Association World Wide.
Lux Fiat