Board Thread:General Discussion/@comment-24726378-20150102200745/@comment-31121580-20180424194609

Ichibei is the oldest zanpaktu as he name everything in SS and even achieved The First bankai without a actual Shallow sword.

Nimiya is the 2nd, he is the creator of the Shallow sword and every shinigami in SS has one including Yamamoto so this dude is obious older

Yamamoto is the flashback 2100 years ago was in his 60s or so, so in 2000 years he aged about 20+ years, so yamamoto should be between 5000-10,000 years old