The first, and likely the "classic" you're thinking of, is the post-apocalyptic action film from Italian director Enzo G. Castellari. It often gets incorrectly dated to 1990 due to its frequent association in box sets and conversations with Castellari's other films from that time period.
The film’s particular brand of fantasy was expanded upon in a sequel released later that same year. This follow-up continued the saga, exploring further time-travel scenarios and the consequences of the magical artifact's power. the new barbarians 1990 classic xxx new
The overall critical consensus seems to be that while it's undeniably a porn film, The New Barbarians is an unusually effective one. It commits to its fantasy world and delivers solid entertainment, with the hardcore scenes serving as a bonus rather than the whole point. The first, and likely the "classic" you're thinking
and Hell of the Golden Sword (1984) : These films might not be exactly what you're looking for due to the date discrepancy, but they do contain "barbarian" in their associated lore or titles. The film’s particular brand of fantasy was expanded