Hello,

BEd is absolutely necessary if you want to teach in KVS or any other similar reputed government schools, nowadays in fact many private schools too ask for BEd, it's believed that trained teachers can impart knowledge in more better manner, the reason being they go through the entire syllabus of BEd programme, and there is lot of learning involved along with practical applications also, when it comes to eligibility for PGT History in KVS, then candidates with MA in History from a recognized university  securing 50% aggregate along with teaching experience in English and Hindi Medium are eligible to apply, however you need to check out the eligibility criteria prior to applying as I told you before that certain universities do emphasize on having studied History at ug level, you can also consider going for distance mode regarding this.