Due to the wide variety of minerals in the Spanish soil (lead, silver, iron, copper, zinc, mercury, coal …), in the first half of the century, particularly after 1840, there was a proliferation of firms focused on mining extraction. The mining activity of the time was conditioned by a regulation that only granted a specific number of concessions. The institutional legal framework had an impact on the mining activity: an extreme division of ownership of the mines, and a fragmentary regulation that made it difficult to control the moves of the mining societies. The “Special Mining Companies Act” passed on June 19, 1859, aimed to regularize this reality. The articles of the law dictated that the company had to have a registered capital and that the shares should be characterized as the shares of a regular corporation (which means, at least, to participate in the expenses, profits, credits and losses of the firm). In this communication, we will analyze the unique characteristics of mining societies compared with other legal forms. We will pay special attention to the role of the legal framework for the development of the “Golden Age” of the Spanish mining. The spatial analyze will be focalized into the Southeast of the peninsula.