Iphone 4 ios 6 has shared calendar with iphone 5 ios7.. Having issues syncing Iphone 4 ios 6 has shared calendar with iphone 5 ios7.. Having issues syncing.  

I have logged on to Icloud and the calendar events are on both accounts. however it is not syncing with either phones... (this is only for the old events only) All new events are showing on both phones.

How do we get the previous events to reflect on calendars on our phones...?
Go to Settings > Mail, Contacts and Calender > Sync

Set it to always and the old events will be synced as well on both the devices.