Pope Francis to declare Mother Teresa a saint at Vatican ceremony.

Blessed Mother Teresa of Kolkata is set to be canonised by Pope Francis at the Vatican on Sunday 4 September, almost 13 years after her beatification in October 2003.

Mother Teresa’s canonisation follows the Vatican’s verification of two miracles attributed to her, the final step required in the journey to sainthood.

The ceremony in St Peter's Square, scheduled for 10.30 on 4 September, will be one of the main events of the Vatican’s Holy Year of Mercy which runs until 20 November.

Tickets for the ceremony, which are free, can be obtained from the Vatican as well as from the Mother Teresa of Calcutta Center in Rome's Piazza S. Gregorio al Celio 2, between the Colosseum and the Circus Maximus.

In 1950 Mother Teresa founded the Missionaries of Charity, a religious order based in Kolkata, formerly known as Calcutta, the capital of India's West Bengal state. Known as the “saint of the gutter”, she dedicated her life to administering help to the city's destitute, in particular the sick and dying.

After the Albanian-born nun died in 1997, at the age of 87, St John Paul II waived the Vatican’s five-year waiting period before beginning the process of being recognised as a saint, leading to Mother Teresa’s beatification just six years after her death.

The work of Blessed Mother Teresa, which is continued by her missionaries in 139 countries, is seen as close to the papacy of Pope Francis whose pontificate has at its core the poor and marginalised.

Sister Mary Prema Pierick is the current superior general of the Missionaries of Charity which numbers more than 5,000 sisters and over 400 brothers.