In his later years, Du Fu wrote quite a few extended regulated poems.
Tips
culture
Per 《新华词典》: 律诗的一种。就律诗定格加以铺排延长 — 'a kind of regulated verse, the lüshi form expanded and stretched out'. Minimum 10 lines (some up to 100 rhymes). Yuan-dynasty editor 杨士宏's anthology 《唐音》 first listed 排律 as a category.
usage
Distinguishing the regulated forms by length: 绝句 (4 lines) → 律诗 (8 lines) → 排律 (10+ lines). All but the opening and closing couplets in 排律 must be strictly parallel — a brutal technical demand that's why few poets attempted it.
