Hyderabad, beyond its chai and biryani fame, holds a unique place in Indian postal history. From 1839 to 1949, the Nizam of Hyderabad's dominions produced over 120 diverse stamps, reflecting the evolving princely state and showcasing their architecture, calligraphy, languages, and more. This also included the world's first adhesive stamp, the Black Penny. Read more such stories only on ThisDay.