Abstract: This article recalls the fact that until the mid-19th century neither company legislation, nor jurists, nor economists, envisioned companies to be private or small. Nevertheless, once freedom of incorporation and general limited liability were enacted, a new practice was set in motion in Britain. Smaller companies were formed in growing numbers, replacing partnerships, family firms and even sole proprietorships. They operated in sectors in which corporations had not been found before. These companies did not seek access to the stock markets. The article tracks the take-up pattern and changing characteristics of the corporate form in Britain between the enactment of free incorporation and general limited liability (1844–62) and the formal legal recognition of the private company (1907). It shows the dramatic increase in annual incorporation and the parallel decrease in the average capital and average number of shareholders in newly formed companies. The article then analyses the reasons for the decision of businesspersons to incorporate their small firms. The main motivations were the possibility to create asset partitioning between personal and business assets and the ability to use the floating charge. Finally, the article examines the legal reaction to the bottom up emergence of the private company. It examines the reactions of the courts (in the famous Salomon v Salomon case) and of the legislature to this unpredicted practice. It argues that incorporators and their lawyers used the available contractual flexibility to privately design Articles of Association and to adjust them to the specific needs of private and small companies, often by introducing partnership internal governance rules into company Articles. The present study relies on newly gathered data on the take-up of the company form and a newly produced sample of company files collected at Companies House and the National Archives.