When studying the role of the History of Mathematics in Mathematics Education Michael N. Fried highlights the role of Encyclopaedias: "The word encyclopaedia is significant. It is a combination of two Greek words, engkuklios and paideia; (...) so that engkuklios paideia is something like the education common to all." What knowledge has there been in Portugal about Mathematics and its greatest practitioners? In this work, we analyse the contents of the History of Mathematics in two Portuguese encyclopaedias from the 19th century: E. M. Campagne - Dicionário Universal de Educação e Ensino. Translated to Portuguese by Camillo Castello Branco (1873); Diccionario popular historico, geographico, mythologico, biographyco, artistico, bibliographico e litterario (1876-1890) directed by Manuel oaquim Pinheiro Chagas (1842-1895). We also briefly discuss the educational context of the 19th century and the possible explanations for the details and shortcomings of the encyclopaedias with regard to the History of Mathematics, especially the Portuguese one, not having found any impact of the pioneering work of Francisco de Borja Garção Stockler (1759-1829) on the History of Mathematics in Portugal edited in Paris in 1819 in the dictionary by Émile-Mathieu Campagne (1835-?) and Camilo Castelo Branco (1825-1890); on the contrary, Manoel Pinheiro Chagas' dictionary contains some references to the international and Portuguese History of Mathematics and also to the work of Garção Stockler.