In 1955, aged 25, he was ordained in London by Cardinal Bernard Griffin and sent to Rome to study Canon Law.
He worked in education and basic pastoral care in Uganda and Kenya and in 1965 as vicar general of the Kenyan Diocese of Kisumu, under the Dutch bishop Jan de Reeper.
For an impressive 42 years, Bishop Willigers led the faithful of his diocese, until he retired in March 2010.
Willigers was inspired by the spirituality of Blessed Charles de Foucauld and was characterised as intelligent, hospitable and warm.
Returning to the Netherlands in ill health, Bishop Willigers took up residence in the Vrijland mission house in Oosterbeek, where he died in the early morning 1 October 2012, in the presence of his sister.