The Philatelic Society of India
The Philatelic Society of India (PSI) was formed in 1897 by a group of, mainly, expatriate Englishmen resident in the country as the first all-India philatelic society. During its first fifty years the society included most of the important Anglo-Indian philatelists and had a particularly strong publications record with two award-winning books.
Source: Wikipedia — The Philatelic Society of India (CC BY-SA 4.0)