What this source establishes
The canonisation itself, 15 May 2022 — a public act of the Holy See, and the highest tier of evidence there is.
This is as much of it as we may lawfully print. The rest is at vatican.va.
2022
The turban and the chains
On 15 May 2022 Pope Francis canonised Devasahayam Pillai, baptised in this church on 14 May 1745 — the first Indian layman ever raised to the altars. What this church holds of him, it has held a long time. At Christmas 1888 a visiting priest wrote that the most precious memory of his day here was the martyr: “Vadakenkoulam possesses the turban he wore, and the chains taken off at his death.” Fr Pouget opened the reliquary and let them look. That head-cloth, worn by an officer of the Travancore court, is kept here still, and every 15 August it is set out in a glass case for the pilgrims to venerate.
DocumentedThis moment rests on 8 sources.