One of my calendars in the list has vanished. It is not simply unchecked, but gone. It was all my own personal appointments, the calendars for other family are all still there. How do I restore that one calendar. I use iCloud and calendars is on.

One of my calendars (one of several) has vanished. It is not simply unchecked, but is totally gone. I have a MacBook Pro, iPad mini, iPhone 5c - this calendar is gone from all devices. I do have and use iCloud and calendars is turned on. I have turned off calendars and back on as well as turned off iCloud and then the device itself. Nothing has worked and this has all my own personal appointments on it. Any ideas of how to restore this one calendar and make it available in my list of the other calendars again?