The World Meeting of Families gets underway in Dublin today.
Last night, bells rang out in all 26 dioceses across the country to mark the start of the event.
It begins with a three day pastoral congress at Dublin's RDS which includes discussions, workshops and prayerful activities.
The event will conclude with the 2-day visit of Pope Francis this weekend.
Meawhile, with 45,000 tickets issued to see the Pope at Knock Shrine on Sunday morning, management at the Shrine are asking those who have tickets and are not planning to use them to pass them onto others - such as friends, neighbours or people in their parish.
As thousands of people across the country were not able to secure tickets, management say it would be greatly appreciated if available tickets are passed onto others who would use them.