This book is not only a complete aid for students of the 1st Lyceum but also a useful guide for educators on teaching Thucydides' History in high school. The approach to the text is functional and innovative, contributing to a deeper interpretation of it. Excerpts from Thucydides' 1st book, which are included in the textbook, are structured in this book into teaching units, facilitating the student's understanding of the knowledge and helping the teacher respond to new educational data.