In 1877 the Public Record Office asked Bliss to go to Rome to do research in the Vatican Archives on its behalf. He accepted the offer and spent most of his time searching the mediaeval Papal Registers in order to find all the dealings between the Papacy and Great Britain and Ireland. This job required Bliss to spend nine months of each year in Rome and this became Bliss' habit until he died at the Via Delphini in 1911. His wife raised the children in England and remained an Anglican.