This project aims to explore the expansion of H39* and its daughter branches, which can be found across the globe with a particular concentration in and around northern Europe. H39 is a mitochondrial DNA (mtDNA) haplogroup defined by the mutation A > G at position 16299 on the HVR-1 region of the mitochondria (represented as “A16299G”); this lineage split from macro-haplogroup H approximately 10,000 years ago, probably in Anatolia or otherwise in the general area of West Asia. Due to the conspicuous absence of haplogroup H in Europe during the Mesolithic and its sudden appearance in association with farming populations, we can assume that H39 arrived in Europe in the Neolithic with groups carrying Early European Farmer ancestry, mixing with local hunter-gatherer populations to varying degrees. There are three major downstream branches of H39 on the FamilyTreeDNA Haplotree: H39a (defined by mutations G709A and C16169T), H39b (defined by mutation T5892C), and H39c (C13362T). H39a is the largest subclade of H39, with the vast majority testers who are positive for this branch listing their earliest known maternal ancestors being from the British Isles and Scandinavia. H39b is a smaller branch that has a distinct British Isles shift in its distribution, but also contains a Swedish kit. H39c is a distinctly Fennoscandian branch with all of its downstream testers listing earliest known maternal ancestors from Finland and Sweden. YFull identifies two other branches named H39d (defined by mutation A2755G) and H39e (defined by mutation T3398C), both of which combined only consist of a few kits; although not yet recognized by FamilyTreeDNA, this project includes kits that would fall under H39d and H39e under "DNA Results". An extended description of haplogroup H39 is provided under the "News" section - feel free to collaborate with users and share any pertinent information you may find!