Cardinal Joseph Zen Ze-kiun, who is 90, arrived for his trial in Hong Kong this week leaning on a walking stick and wearing a face mask, with just one companion and no retinue. He has faced prosecution with the same mildness and calm with which he has always conducted his ministry.

An interview with Cardinal Zen was a lesson in humility rather than an encounter with pomp. He received me in a small room adjacent to the sacristy in the Cathedral of the Immaculate Conception. His voice never rose, even though this was during one of the periods of tension that beset his time as Bishop of Hong Kong from 2002 to 2009. The Chinese were arresting bishops. The Vatican was conducting quiet diplomacy with Beijing. From the sidelines, the Cardinal Kung Foundation, a fervent exile group in the US, cast anathema on all compromise. Zen, living under Chinese rule in Hong Kong, with fragile guarantees of religious freedom, was caught in the middle.

For a clergyman, he did a nice line in irony. He did not criticise his superiors but noted that a delegation from the Chinese government’s Religious Affairs Bureau and state security apparatus was “received very kindly and given a privileged tour of the Vatican and of the Sistine Chapel one Sunday”. Cardinal Zen was used to interviews, although one got the impression that he disapproved of the way that newspapers treated persecution as manna for headlines.