The Catholic leader addressed Christians near to a ransacked church in Mosul, which became a stronghold for the terrorist group before it was defeated.

Speaking to a packed Church of the Immaculate Conception, Pope Francis stressed ‘forgiveness’ as a key word for Christians.

The historic mass came after IS seized northern and western Iraq in 2014 and used Mosul, Iraq’s second-largest city, as a major base. Christians who lived there suffered a host of human rights abuses at the group’s hands.

Surrounded by the grey, hollowed-out shells of four churches that were almost destroyed during the war, the Pope said: ‘The road to a full recovery may still be long, but I ask you, please, not to grow discouraged.

‘What is needed is the ability to forgive, but also the courage not to give up.’

He added: ‘How cruel it is that this country, the cradle of civilisation, should have been afflicted by so barbarous a blow with ancient places of worship destroyed and many thousands of people – Muslims, Christians, Yazidis – who were cruelly annihilated by terrorism – and others forcibly displaced or killed.’

The Pope addressed a crowd at the square near the ruins of the Syriac Catholic Church of the Immaculate Conception in Mosul

There had been fears that the gathering could spread coronavirus in the area, despite the service taking place outside.

Then he deviated from his prepared speech to address the plight of Iraq’s Yazidi minority, which was subjected to mass killings, abductions and sexual slavery at the hands of IS.

He continued: ‘Today, however, we reaffirm our conviction that fraternity is more durable than fratricide, that hope is more powerful than hatred, that peace more powerful than war.’

The Pope’s visit was intended to encourage Christians to return to and to stay in Iraq, where Christian communities have existed for thousands of years.

Before the US-led invasion of the country some 1.5 million Christians lived there. During the war, IS forced people to choose between conversion, death or paying a special tax for non-Muslims.

Many public health officials worried about the coronavirus dangers of people gathering to meet the pope

The Pope held a minute of silence at a destroyed cathedral in Mosul

Francis released a white dove, the symbol of hope, while he addressed followers in Iraw

The war forced thousands to flee, leaving behind homes and churches that were destroyed or commandeered by the group, and today there are just a few hundred thousand Christians in Iraq.

Pope Francis says he wants to help the remaining Christians stay and help rebuild the country and restore what he called its ‘intricately designed carpet’ of faith and ethnic groups.

It took a ferocious nine-month battle to finally free the city of Mosul in July 2017, during which time between 9,000 and 11,000 civilians were killed, according to an AP investigation at the time.

Is leader Abu Bakr Al-Baghdadi was killed in a US raid in Syria in 2019.

The war left a trail of destruction in Mosul and the north, and many Iraqis have been left on their own to rebuild amid a long financial crisis.

Pope Francis enjoyed a four-day trip in Iraq to encourage Christians to stay in the country and help rebuild it

The Reverend Raed Kallo was among the few Christians who returned to Mosul after IS was defeated.

He added: ‘My Muslim brothers received me after the liberation of the city with great hospitality and love.’

Before IS, he had a parish of 500 Christian families. Most emigrated abroad, and now only 70 families remain.

But he said: ‘Today I live among two million Muslims who call me their Father Raed.’

Gutayba Aagha, the Muslim head of the Independent Social and Cultural Council for the Families of Mosul, encouraged other Christians to return.

The Pope conducted Mass at Franso Hariri Stadium in Erbil, as the last stop in his trip

The Pope also had a historic meeting with Iraq’s top Shiite cleric, Grand Ayatollah Ali al-Sistani

‘In the name of the council I invite all our Christian brothers to return to this, their city, their properties and their businesses,’ he said.

Pope Francis delivered similar messages when he visited nearby Qaraqosh, saying: ‘Forgiveness is necessary to remain in love, to remain Christian.’

During the Pope’s four-day trip he also held a historic meeting with Iraq’s top Shiite cleric, Grand Ayatollah Ali al-Sistani.

The trip grew criticism for going ahead during the pandemic. Although Francis has been vaccinated, Iraq only received its first batch of vaccine supply last week.

At the Pope’s last event, addressing thousands at a stadium in Irbil, he said Iraq would stay in his heart.