The Unification Wars
Half-Elves are what you get when you cross an Elf with a Human. Slightly taller than a Human, yet more stocky than an Elf. The men are able to grow facial hair and even beards, something that no Elf can do, which they sometimes do to hide their Elven heritage. They age into adulthood at the same time as Humans at around 20 years of age, and then remain in their prime until they are around 150 years old, before living on average to around 180 years if they were to die of old age, with very few outliers living closer to Human numbers, and some living centuries in line with their Elven heritage. They will either live in Human cities and be viewed as an Elf, or more rarely, live in Elven forests and be viewed as a Human. Therefore to avoid conflict, many Half-Elves prefer to live alone if possible.
Naturally charismatic, Half-Elves are able to defuse dangerous social situations, and learn at an early age to get along with other races. Thus they make excellent diplomats for adventuring groups, cities, race relations, and even nations. The only groups that distrust a Half-Elf ambassador are Humans and Elves during a dispute, each thinking the Half-Elf favours the other group. A Half-Elf gains traits from both sides of their heritage, with their appearance ranging from any of their joint lineages, with their eyes favouring Elven colours and their hair favouring their Human ancestry.
Any of the sub-races of the Elves can create a Half-Elf child with a Human, however a Half-Elf’s children can only ever be Human or Elven, leading to many Half-Elf parents outliving their children, or being unable to provide their child with their people’s history. Therefore many Half-Elves choose not to procreate or at least not form a family, preferring to remain aloof. The only people who understand a Half-Elf’s point of view is another Half-Elf, but two Half-Elves cannot have children, further cementing this race as aimless wanderers, helping out strangers on the road, or swindlers of the gullible in society, using their charismatic attitude for personal gain.
As with the Elves, Half-Elves reproduction is based around a tree and the spirit that embodies the tree, though only the most desperate and sometimes sickly of tree spirits choose a Half-Elf as a bonded life, which results in their shorter lifespan.