Well, let's see. Off the top of my head, on the large scale there's Ariosto's Five Cantos, his unfinished sequel to Orlando Furioso, which not only makes allusion all over but breaks off in almost the exact same way -- so speculations that it is deliberately unfinished. In English, Samuel Daniel's The Civil Wars -- though he somewhat civilized the influence. If you can't find a copy (cheap ones are hard to come by) angevin2 transcribed it with modernized spelling under this tag.

Plus umpteen-dozen allusions on the small scale.

---L.