Modelling History Through Cycles

[Sindri]

So I've been looking for whatever long term cycles people have suggested exist for use in modeling history and producing timelines. Infinite World's Development section of History, Already in Progress starting on pg. 99 has been quite useful but I thought I'd ask if any one knows of specific cycles or trends not mentioned there or has thoughts on using stuff like this for their world's history while I'm reading through the literature.