Seven Holy Cities
Very rare1.0%All-the-thingsOptionalSingle-player
As a Hindu ruler, hold all seven Hindu Holy Sites at the same time
The seven Saptapuri counties, all in your realm at once, as any Hindu ruler - the holders don't need your religion, they just need to be yours (or you). Maharaja Bhoja of Pratihara, 867, starts controlling all but ONE of them, so this is nearly a one-war achievement: grab a CB on the remaining holder, take the county, done. Convert to Smartism (or Kalikula Shaktism) if you want the faith view to track the exact sites for you - their site list matches the achievement's set.