duplicating data

I have encountered a task that i need to do with a SQL database and cant figure out how.

There are two tables, one with event and date columns and the other with era and start date. Bascially events, are a list of events throughout history and the day they occured and the second is the startnig day of periods in history. I would like to output the event and date columns along with another column that lists the period for that date. So the third column would hold alot of redundant information, entries repeating up to the date where the era switches.

Could someone suggest a way to do this?