During the 16th century, the dissection of human bodies was highly prohibited by the Church. Therefore, in order to combat this opposition, Vesalius had to secretly take the bodies of executed criminals, a process which he explains in De Humani Corporis Fabrica. This process of stealing the dead bodies of criminals was a key way for anatomists and artists to study the human body. For example in 1828 the case of Burke and Hare, whereby the bodies were delivered to anatomists for dissection, were murdered specifically for financial gain.