Even though both Herophilus and Erasistratus had permission to use cadavers for dissection there was still a lot of taboo surrounding the use of cadavers for anatomical purposes, and these feelings continued for hundreds of years. From the time that anatomical dissection gained its roots in the 3rd century to around the 18th century it was associated with dishonor, immorality, and unethical behavior. Many of these notions were because of religious beliefs and esthetic taboos, and were deeply entrenched in the beliefs of the public and the church. As mentioned above, the dissection of cadavers began to once again take hold around the 12th century. At this time dissection was still seen as dishonorable, however it was not outright banned. Instead, the church put forth certain edicts for banning and allowing certain practices. One that was monumental for scientific advancement was issued by the Holy Roman emperor Frederick II in 1231. This decree stated that a human body will be dissected once every five years for anatomical studies, and attendance was required for all who was training to or currently practicing medicine or surgery. These events are what led to the first sanctioned human dissection since 300 B.C. and was performed publicly by Mondino de Liuzzi. This time period created a great deal of enthusiasm in what human dissection could do for science and attracted students from all over Europe to begin studying medicine.