General terms:
* Epic: This term usually refers to a long narrative poem, but it can also describe a story with a grand scope and long duration.
* Saga: This term usually refers to a long, often historical, story about a family or a nation, passed down through generations.
* Chronological: This simply means the story is told in order of time, implying a long period of time covered.
* Multi-generational: This term emphasizes the story's focus on multiple generations.
* Historical: This indicates the story takes place over a significant period of historical time.
* Spanning Decades/Centuries: This is a more specific way of indicating the story's time frame.
Genre-specific terms:
* Family saga: This is a specific type of saga focused on the lives and relationships of a family.
* Historical fiction: This genre often features stories set over long periods of time, focusing on specific historical events or periods.
* Fantasy epic: This genre often features long narratives, spanning centuries or even millennia, with grand themes and world-building.
Other options:
* Generational story: This term emphasizes the passing of time through the lens of different generations.
* Time-spanning narrative: This is a neutral and descriptive term that simply indicates the story covers a significant period of time.
Ultimately, the best way to describe a story stretching over a long period of time depends on the specific content and your intended meaning.