A recent field, the History of Mathematical Education has gathered its researchers and other professionals in different journals and scientific events in the field of Education and Mathematical Education. Two specific events stand out, National Research Meeting on History of Mathematics Education - ENAPHEM (Encontro Nacional de Pesquisas em História da Educação Matemática), started in 2012, whose 5th edition took place in 2020, and Ibero-American Congress on History of Mathematics Education - CIHEM (Congresso Ibero-Americano de História da Educação Matemática), whose 6th edition will take place in 2021, in Venezuela.

The publication of this Dossier “History of Mathematical Education” is another milestone in the growing and fruitful academic production in this field. The set of articles selected for this publication - in addition to many others also approved and which will be published opportunely by this journal - demonstrates the different sources that have been mobilized by researchers in the production of the History of Mathematical Education, its different and renewed themes, theoretical and methodological approaches. It also contemplates the Brazilian geographic and institutional diversity, encompassing researchers linked to several research groups and Postgraduate Programs, also relying on the expertise of international researchers.

This publication was organized and takes place during a period of social isolation due to the global pandemic caused by the Covid-19 disease. We record here the memory of more than 2 million dead people in the world, with more than 270 thousand deaths only in our country until mid-March 2021. Our solidarity to all the relatives of the victims. In the course of organizing the Dossier, our friend, professor Dr. Ivete Maria Baraldi, died on 1/18/2021, as a result of Covid 19. She was very involved and excited about this activity. Ivete was an incredible woman. Ronaldo's wife, together had the boys Pedro and Matheus - for whom she had an unconditional maternal love and unspeakable pride. She always shared conversations (and stories) with her children, her achievements, her ways of seeing and acting in the world. Graduated in Sciences, with qualification in Mathematics in the 1st class of this course as part of the São Paulo State University (Unesp) - campus of Bauru. Master and PhD in Mathematics Education at Unesp, campus of Rio Claro, she joined the Department of Mathematics as a professor in 2008, with outstanding performance in the Mathematics Degree course, also joining the Postgraduate Programs in Education for Science and the one of Mathematics Education, campus of Unesp from Bauru and Rio Claro, respectively. Competent researcher and always attentive, she participated in the training of many teachers and new researchers. In her researches, she studied different aspects of Mathematics Education, such as the Training of Mathematics Teachers, the History of Mathematics Education, Inclusive Education, Teaching and Learning of Mathematics and Oral History. She actively participated in the Research Groups: "Oral History and Mathematical Education" - GHOEM ("História Oral e Educação Matemática") and "The inclusion of people with disabilities, TGD / TEA or giftedness and the contexts of learning and development". To professor Doctor Ivete Maria Baraldi, all our gratitude and our recognition.

We hope that this Dossier can provoke reflections, stimulate actions and subsidize debates both in the field of research in the History of Mathematical Education and in relation to the construction of negationist narratives nowadays.