I read in the book of true lineages, about the founder Mercere being the first of the founders to join Trianoma’s cause. But I did not find in the book any related date about events in his life. Could anyone tell me the date when he died? or when did he lose his gift helping Bonisagus in his laboratory?
I'm not sure there are any dates given.
Tmk Mercere died in the late 820s. You need to check HoH:TL p.80f carefully against the rest of the history of the Order to verify it.
Mercere died in 818, and he lost his gift in 773
See the timeline in HoH:TL p 144
Thanks for the help guys