Who was in charge of knowledge prior to the 1500s?

Scholars

Explanation:

Today the relevance of scholars is not as important as it used to be prior to the 1500s when they were the custodians of knowledge.

In those days scholars as the intellectuals of the day were given the role and responsibility of maintaining the knowledge of society and as such they were referred to when issues of right and wrong arose. They would then offer opinions on these issues based on the wealth of knowledge at their disposal including ancient texts and religious sources like the Bible and the Quran.