Pope Francis has arrived in the Republic of Ireland's first papal visit for almost 40 years.
The Pope is expected to meet some victims of clerical sex abuse later on Saturday.
In a letter to the world's 1.2 billion Roman Catholics, the Pope this week condemned the "atrocities" of child abuse and clerical cover-ups.
The visit coincides with the World Meeting of Families - a global Catholic gathering held every three years.
It will end with a Mass for 500,000 people at Phoenix Park on Sunday, reports BBC.
The Pope was presented with flowers and vestments by children at the airport.
He then travelled to Áras an Uachtaráin, the Irish president's residence, where he has been welcomed by President Michael D Higgins, his wife Sabina and a military guard of honour.
The Ireland that he is visiting is a different country to that which greeted Pope John Paul II in 1979.
Since the Polish pope's visit, there have been huge changes in public attitudes to social issues including abortion, contraception, divorce and same-sex marriage.
The country voted for constitutional change on gay marriage in 2015 and voted overwhelmingly to overturn its strict abortion law in May.
The Irish Catholic Church has been engulfed in scandal with the uncovering of widespread clerical sexual abuse of children and cover-ups.
Child sex abuse scandals continue to embroil the Church around the globe.
On Friday, Leo Varadkar, the Irish prime minister (taoiseach), said he hoped Pope Francis's visit would mark the beginning of a new chapter in Ireland's relationship with the Church.
"In the past the Catholic Church had too much of a dominant place in our society," he said.