Firstly, I read through the rules and I think this post is appropriate, so here goes.. (If not, I'm sorry.)
I bought this decorative sword from a friend of mine awhile back, but he didn't remember what it was called. Can anyone here identy what type of sword it was based on?
Its a really poor knockoff of the sword Robin Hood uses in the 1991 film Robin Hood: Prince of Thieves. You can see it in the cringe-worthy trailer for the (also cringe-worthy) film at the 1:03 mark.
The film sword is pretty much pure Hollywood fantasy.
You can buy yourself a second one, here.
It's very loosely based on a medieval longsword, probably from the late 13th century. It seems most similar to a type XIVa longsword but with a smaller fuller (groove in the middle). The inscription Robin of Locksley on the pommel indicates its attributed to Robin Hood, who may or may not have been a real person.
It's simply a medieval inspired decorative piece meant to resemble pictures of swords that most people saw in books growing up, but not based on any historical examples that I am aware of. Also consider r/swords as there are plenty of people who know a lot more about swords there than I do.