I want to identify the plugin names earlier activated on my WordPress site.
Unless you had something installed to track it, then no, that information is lost.
WP does not track that information out of the box. Post revisions are the closest thing you will find to an audit log, and those only track changes to posts.
You have 2 options to retrieve it:
- Try to remember which plugins were active
- Hope that you have backups from that time you can restore and check