A pretty concise version of the Tony Ryan story going back to the beginning of GPA can be found in this book:
Ryanair: How a Small Irish Airline Conquered Europe
Siobhan Creaton
It's a rattling good read from the biz point of view. Brings the story up to about a year or so ago. Love or hate Ryanair, it is a remarkable story. You will find it's not just OLeary who made it as successful as it is.
If you are not bothered reading it, Tony Ryan did get down to his last few million when the GPA floatation imploded. But of course now the situation is very different - how many €100million's he has now - who knows?