I've got a character whose name needs some sort of number on the end (IV, V, etc.) because his family, particularly men with his name, comprise a hugely important part of the backstory (he's doing family research, so he'll eventually figure out this significance). Here's my problem: The most crucial ancestor to this story (starts a tradition which the story focuses around) was in his 40s-50s around the turn of the 20th Century, and he was the First. I can't figure out what number to give my MC, who was born in 1983, knowing the average human generation is 25 years. Any thoughts?