Saint Francis of Assisi’s skeleton is going on full public display from Sunday for the first time, in a move that is expected to draw hundreds of thousands of visitors.

Inside a nitrogen-filled plexiglass case with the Latin inscription “Corpus Sancti Francisci” (the body of Saint Francis), the remains are being shown in the Italian hillside town’s Basilica of Saint Francis of Assisi.

St Francis, who died on 3 October 1226, founded the Franciscan order after renouncing his wealth and devoting his life to the poor.

Giulio Cesareo, the director of communications for the Franciscan convent in Assisi, said he hoped the display could be “a meaningful experience” for believers and non-believers alike.

Cesareo, a Franciscan friar, said the “damaged” and “consumed” state of the bones showed that St Francis “gave himself completely” to his life’s work.

His remains, which will be on display until 22 March, were transferred to the basilica built in the saint’s honour in 1230. But it was only in 1818, after excavations carried out in utmost secrecy, that his tomb was rediscovered.

Apart from previous exhumations for inspection and scientific examination, the bones of Saint Francis have only been displayed once, in 1978, to a very limited audience and for only one day.

Usually hidden from view, the transparent case containing the relics since 1978 was brought out on Saturday from the metal coffer in which it is kept inside his stone tomb in the crypt of the basilica. The case is itself inside another bullet-proof and anti-burglary glass case.

Surveillance cameras will operate 24 hours a day for added protection of the remains.

Saint Francis is Italy’s patron saint and a public holiday is to be reinstated on 4 October to mark the 800th anniversary commemorations of his death.

Reservations to see the saint’s remains already number “almost 400,000 (people) coming from all parts of the world, with of course a clear predominance from Italy”, said Marco Moroni, the guardian of the Franciscan convent. “But we also have Brazilians, North Americans, Africans,” he added.

During this usually rather quiet time of year, the basilica usually has 1,000 visitors a day on weekdays, rising to 4,000 at weekends. The Franciscans said they were expecting this to rise to 15,000 visitors on weekdays and up to 19,000 on Saturdays and Sundays for the month-long display of the remains.

“From the very beginning, since the time of the catacombs, Christians have venerated the bones of martyrs, the relics of martyrs, and they have never really experienced it as something macabre,” Cesareo said.

Experts said the extended display of Saint Francis’s remains should not affect their state of preservation. “The display case is sealed, so there is no contact with the outside air. In reality, it remains in the same conditions as when it was in the tomb,” Cesareo said.

The light, which will remain subdued in the church, should also not have an effect. “The basilica will not be lit up like a stadium,” Cesareo said. “This is not a movie set.”