g1smd - 9:06 am on Aug 12, 2013 (gmt 0)
When you clear old events and the URL will never be re-used it is more appropriate to return "410 Gone".
However, do recurring events have a new URL each year, or do you re-use the old one? This is an important point, and one worth thinking about. Over time, a re-used URL for such a page will continue to gain many links.