The first diplomat the Holy See sent as its Permanent Observer, Alberto Giovannetti, was a priest rather than a bishop. He had not yet risen to the rank of apostolic nuncio, the senior rank of the Vatican diplomatic corps.
The second Permanent Observer, Giovanni Cheli, was given the personal rank of nuncio and ordained a bishop in 1978 after five years representing the Holy See at the U.N.[1][a] Since then all those appointed to the position have been titular archbishops with the rank of nuncio.