This article is to present my findings found through the analysis of the reo and mātauranga embedded in the manuscripts and publications of Hare Hongi (also known as Henry Matthew Stowell). The particular focus of this article is his book, Māori-English Tutor and Vade Mecum written in 1911. Hare Hongi was taught at a young age in a traditional whare wānanga and was later educated in a Pākehā society. He was the holder and acknowledged guardian of extensive ‘mātauranga’ pertaining to Te Tai Tokerau, in particular mythology, genealogy and cosmology. He was equally capable in the ‘Pākehā world’ and thus recorded and published a great extent of this knowledge. Many of these publications appear in the Journal of the Polynesian Society. The knowledge contained in Māori-English Tutor and Vade Mecum is of fundamental importance to the people of Te Tai Tokerau today, and can provide current and future generations with valuable information and insight into the traditions, whakapapa, reo and tikanga of our tūpuna. This article presents some of the hidden aspects of the publication and the mātauranga it holds, and indicates the relevance of this mātauranga to the people of Te Taitokerau today.