Medak Cathedral is the seat of the Bishop in Medak for the Church of South India (comprising Wesleyan Methodist, Congregational and Anglican missionary societies – SPG, WMMS, LMS, CMS, and the Church of England). The Cathedral is the largest of all churches in Telangana. The Cathedral also sees over the Diocese of Medak, which is the single largest diocese in Asia and the second largest diocese in the world. It was consecrated on 25 December 1924. Built by the British Wesleyan Methodists, the Cathedral is now under the jurisdiction of the Church of South India.
The cathedral was built under the stewardship of Reverend Charls Walker Posnett who was driven by the motto My best for my Lord. Rev. Posnett arrived in Secunderabad in 1895. He first ministered among the British soldiers at Trimullghery. Unsatisfied with the army work, he launched forth into villages. In the year 1896, Rev. Charles Walker Posnett visited a village called Medak and built a bungalow there by staying in dock bungalow. There was no railway route to Medak in those days. The journey of 60 miles (97 km) from Hyderabad had to be done on horseback and Rev. Posnett could do it in a day. There were then hardly two hundred Christians in the whole of Medak area. When he came to Medak, there was a small tiled house as the place of worship. As the number of Christians increased, he felt the need for expanding the church building. Rev.Posnett soon raised a moderate structure on that very spot just enough for the Christian community within the Mission Compound in the traditional shape of a church. He thought it was not a worthy place for divine worship. He started building the present Cathedral in 1914 on a sprawling 1,000 acres (4.0 km2) of land in Ghusnabad area. The foundations for the new church were laid in the beginning of the year 1914. During the early part of the 20th century, Medak district was reeling under famine and Rev. Posnett in order to provide succour to the suffering masses gave the masses employment in the construction of the church instead of running a free kitchen. The construction work on the cathedral went on for 10 years. The cathedral was consecrated in 1924 by Rev. Posnett expressing his grateful thanks to God for mitigating the sufferings of the people. When several Christian groups became re-united as the Church of South India, the church became the cathedral church of the diocese of Medak in October 1947.