2:1 in second year... is it possible to get a first in my final?

I got a 2:1 in my Second year at 65% - my course is weighted 40:60... I coasted a lot in second year, didn't get any firsts in essays because I left them till last minute, but got firsts in presentations because I worried and put my all into them because I'm a nervous speaker.

History is an entirely subjective course, with marking being all over the place so this worries me that it isn't possible, I've never found my degree particularly hard and getting the 2:1 this year was easy but obviously final year is far harder. Has anyone managed to go from a mid or low 2:1 in second year to a 1st in final year in any humanities subject, but more specifically history? If so, what changed from your second year?