Valakis, also known as Menk, was a planet that was home to two sentient species, the Menk and the Valakians. Since 2236, Valakis was the capital of the Commonwealth of Menk and Valakis and a member of the United Federation of Planets. (ST reference: Star Charts)
When the Valakians were the dominant species, they provided the Menk with land, food, clothing and other resources in exchange for their services.
By the 22nd century, a genetic mutation was causing the Valakian population to decline. This led to a planetary wide epidemic, with a cure seeming to evade the Valakian scientists. They sent several sublight ships into space, hoping to discover another species who could help them.
One space shuttle was discovered by United Earth starship Enterprise, who at first offered their assistance. However, when Dr. Phlox discovered the Menk were an evolving species, the Enterprise left, hoping the Valakians will find a cure on their own. (ENT episode: "Dear Doctor")
In 2236, Valakis was admitted into the United Federation of Planets following their discovery of warp drive. By that time, the planet was renamed Menk following a shift in power. By 2236, the population of Menk had reached to the tens of millions while the population of the Valakians was only a few hundred thousand. (ST reference: Star Charts)