BUFF - SAGE'S BLESSINGS

I have a new account in a new server; my old account has this Sage's blessing buff.

--Anybody here knows the condition on obtaining the "SAGE'S BLESSING"? Please I need to know, I remember we were taking a city (forgot what level) then it just appeared permanently after we've occupied it.

***basically it gives you a huge exp, production, gathering, upgrading (research, dragon, building) buffs***

If anyone knows, please comment on the post. Thank you!!🫶🫶