Battle of São Mamede Directory References Discover Nostradamus and His Prophecies Will Light-Speed Space Travel Ever Be Possible? What Do Eggs Have to Do with Easter? 12 Greek Gods and Goddesses Why Is Ireland Two Countries? 6 Wars of Independence 7 of the World’s Deadliest Shipwrecks Contents Ask the Chatbot a Question Battle of São Mamede Portuguese history Ask the Chatbot a Question Learn about this topic in these articles:victory of Afonso I In Afonso I…his party prevailed in the Battle of São Mamede, near Guimarães (1128). Though at first obliged as a vassal to submit to his cousin Alfonso VII of Leon, Afonso assumed the title of king in 1139.Read More Britannica ChatbotChatbot answers are created from Britannica articles using AI. This is a beta feature. AI answers may contain errors. Please verify important information using Britannica articles. About Britannica AI.