A London-born boy has become the first millennial saint, in a ceremony steeped in an ancient ritual presided over by Pope Leo on Sunday.

In his short life, Carlo Acutis created websites documenting “miracles” as a means of spreading Catholic teaching, leading some to nickname him God’s influencer.

His canonisation had been due in late April but was postponed following the death of Pope Francis.

More than a million people are estimated to have made a pilgrimage to the Italian hilltop town of Assisi where Carlo’s body lies, preserved in wax.

But there is another pilgrimage site associated with Carlo Acutis that has seen an increase in visitors since it was announced that he was to be made a saint – Our Lady of Dolours Church in London – the church he was baptised.

His family returned to Italy shortly after Carlo’s baptism where he was known for his love of technology and video games.

While some who knew Carlo Acutis say he did not appear to be especially devout, as a teenager he did create a website – pages of which are now framed at the church in Chelsea – in which miracles were documented. But he died of leukaemia aged just 15.

Pope Francis attributed two miracles to Carlo Acutis which made him due for sainthood on 27 April.

Approval for someone to become a saint can take decades or even centuries, but there is a sense that the Vatican fast-tracked Carlo Acutis’ canonisation as a means of energising and inspiring faith in young people.

The Catholic Church will be hoping Sunday’s events do just that.