[1][3] Brought up in inter-war London, Susan Lowndes was therefore always surrounded by books and met many writers who visited the family home.

In August 1938 she went with her father for a brief holiday in Lisbon, where she met Luís Artur de Oliveira Marques (1898-1976), an English-educated journalist.

Their son, Paulo Lowndes Marques, recalled visits to Lisbon from Evelyn Waugh, Cyril Connolly, Aldous Huxley and Graham Greene.

Luís was referred to by Joseph Goebbels as “a man to be destroyed” and in a German propaganda radio programme the paper was called “the voice of Churchill in Lisbon”.

As a consequence, the couple was on the special embassy list for immediate evacuation should Portugal have been invaded and a large sum of cash was always kept at their house just in case.

It involved the two authors in travelling throughout Portugal on poor roads in search of interesting places to recommend to potential visitors.

Together with her elder sister, Elizabeth, Countess of Iddesleigh, she edited The Diaries and Letters of Marie Belloc Lowndes (1971), which described the atmosphere of the interwar years in London.

Paulo Lowndes Marques (1941-2011) was a lawyer, historian, a founding member of the CDS – People's Party and Secretary of State for Foreign Affairs in Portugal.