the population follow non-Christian religions and the percentage of the non-religious population varies between around 6% in the Azores and Madeira and 23.1% in Lisbon. In 124 of the 308 municipalities, over 90% of the population indicated being Catholic in the 2021 Census. The municipalities with the highest percentages are Mesão Frio (97.0%), Ribeira de Pena (96.5%), Resende (96.4%) and Baião (96.3%) in the North region, and Vila Franca do Campo (96.3%) in the Azores. The least Catholic municipalities are located in the Algarve and on the Alentejo coast with Lagos (55.2%), Vila do Bispo (56.1%), Sines (56.2%), Aljezur (56.3%) and Odemira (56.7%) with the lowest percentages . The municipalities with the highest proportions of members of other Christian denominations are Lagos (14.3%), Albufeira (13.2%), Portimão (12.7%), Loulé (11.3%) and São Brás de Alportel (11.0%), all in the Algarve. The municipalities with the highest proportion of followers of non-Christian religions are Odemira (16.5%), Albufeira (4.1%), Lisbon (3.9%), Odivelas (3.4%) and Amadora (3.2%), in the Alentejo, Algarve and Lisbon regions. With regard to the non-religious population, the highest percentages are registered in parts of the Alentejo and the Algarve with Sines (35.5%), Vila do Bispo (33.7%), Grândola (31.7%), Aljezur (31.5%) and Aljustrel (31.4%) recording the highest percentages. In 15 municipalities more than a quarter of the population is not religious. On the other hand, in 74 municipalities this percentage is less than 5%. There is a very considerable difference in terms of religious composition between the inhabitants with Portuguese nationality and the foreign population residing in the country, which makes up 5.2% of the total population. 82.6% of residents of Portuguese nationality are Catholic, while only 36.4% of foreigners identify with the Catholic Church. Just over 3% of Portuguese nationals belong to other Christian denominations, a percentage that approaches 30% among foreign residents. Only 0.6% of residents of Portuguese nationality reported belonging to non-Christian religions, with this percentage being 12.3% among foreigners. As for the population without religious affiliation, the percentage is 13.7% among residents born in Portugal and 21.5% among residents born abroad. History As in most provinces of the Roman Empire, the religious beliefs and deities of the Pre-Roman populations mingled and coexisted with Roman mythology. In the Portuguese case, those Pre-Roman religions were basically Proto-Celtic or Celtic, chief amongst them that of the Lusitanians (see Lusitanian mythology). Jewish populations have existed in the area, going back to the