RTÉ Deputy Foreign Editor Fiona Mitchell looks back on one of the most momentous days in the Catholic Church's recent history

What a difference a year makes.

Exactly 12 months ago today the world was told that Pope Benedict had resigned – the first Pope to do so in almost 600 years.  

I was in Rome when news broke and the reaction across the city was one of utter shock. In fact at first many people had the same response – "but a Pope can’t resign".

Of course we know better now.

The first news of the resignation broke on Ansa, a leading Italian news wire, sending a flurry of anxious calls across Rome and Vatican City. 

Soon the news had filtered out of how the Pope had told a gathering of Cardinals that he no longer had "the strength of mind and body" to continue in his post.

In a place like Rome, where so much of the city’s cultural and political life revolves around the Vatican, it was a seismic announcement. 

The list of questions was immediate – why had Pope Benedict done this? How would two Popes function in one Vatican? Where would Pope Benedict live now? When would there be a conclave to elect a successor? Even down to the most basic of questions – what would he be called?

It’s rare to be able to see news of a story physically spread but this was one of those occasions.  As I made my way to St Peter’s Square you could see people stopping in the often chaotic Rome streets to read mobile phone screens as texts and social media sites spread the news.

The shocking nature of the announcement was no where more evident than in St Peter’s Square itself where locals, tourists and journalists gathered.

The growing number of journalists told its own story.  Within an hour there were reporters lined up in every available space, speaking every language imaginable.

An hour later the figure had doubled and as the day wore on the media frenzy continued as broadcasters arrived from throughout the world.

The reality of course is that most journalists were struggling to explain a story for which there was no precedent in living memory.

The fact that Pope Benedict had kept the news such a closely guarded secret meant that even the Vatican Press Office struggled to provide the answers from the flood of media inquiries.

Many pilgrims and tourists who had started their morning sightseeing in the Vatican found themselves being interviewed by broadcasters from across the world, keen to see how people felt about such a momentous decision.

Even seasoned Vatican watchers could only suppose how any new arrangement would work.

Vatican City is a small geographical area in the city of Rome – just over 100 acres of ground and less than 900 inhabitants – but at the moment the announcement was made it became the focus of world attention – attention which would continue for weeks to come.

It also became the focus of torrential rain as a thunder and lightning storm lit up the afternoon and evening sky.

It even resulted in one photograph of lightning hitting the dome of the Basilica – a shocking image to match a shocking day.

In retrospect though, the most  shocking element of the event is how easily it all seems to have happened, and how within the last twelve months it has become utterly normal for two Popes to live in Vatican City side by side.

When we were told that Pope Benedict would live in a converted convent in the grounds of Vatican City many said it would be impossible.  A man who had ruled the Church for eight years would not be able to simply walk away.

Yet Pope Benedict has chosen to stay out of the spotlight, apparently perfectly content to leave his successor to the job of ruling the worlds one billion Catholics. 

The two Popes seem to have a very amicable relationship.  They often spend time in one another’s company and have been pictured together on numerous occasions.

A year ago today that would have been unimaginable but then again, what a difference a year makes!