With some justification Pope Pius XII claimed that the Virgin Mary had saved Portugal (for the Church). And indeed, both the timely dedication of the nation to her Sacred Heart before the 1940 concordat, and a papal pilgrimmage to her shrine in Portugal before the 2004 concordat seemed calculated to help the negotiations.
In this secretly signed concordat even the dictator Salazar was reluctant to cement Catholic religion classes in state schools and to outlaw divorce for Catholics. However, on both points the Vatican prevailed. Thus Article 24 denied Catholics their civil right to a divorce until democracy was restored.
Salazar put the remains of the far-flung Portuguese Empire under this concordat. After World War II, when other European countries were beginning to withdraw from their colonies, he refused to give them independence. Although his regime was overthrown in 1974, Portuguese colonies and even ex-colonies continued to be governed by this concordat until the new concordat of 2004.
This concordat was signed in secret in the Vatican by the Portuguese Prime Minister Barroso and only announced afterwards, (a procedure repeated by the President of Brazil in 2008). The agreement introduces a church tax (Art. 26.1) and maintains the teaching in state schools of "Catholic morality" by people appointed by the bishops but paid by the state (Art. 19).
