Preeclampsia is a pregnancy-specific syndrome with an unknown etiology. In ancient Greece, Hippocrates first described the condition when he wrote in one of his Aphorisms that convulsions take place from either repletion or depletion of the four humors. He also observed the sudden and unexpected appearance of maternal convulsions. The word eclampsia was attached from the Greek for lightning. During the Middle Ages, medical and scientific progress came to a standstill, because Christians were opposed to science and forbade human dissection. Before long, Christian influence began to decline, and Salernitana and Arabian influences increased. With this newfound freedom, anatomist and artists were able to describe accurately the female reproductive tract. In the Early Modern ages, the beneficial effect of delivery on convulsions was recognized. In addition, it was suspected that causative factors of convulsions were probably toxic agents which originated in the decomposing fetus. In the Modern Ages, the measurement and recognition of high blood pressure was made possible by the introduction of Riva Roccis sphygmomanometer, and proteinuria in eclamptic women was recognized. At the turn of the 19th century to the 20th, the presence of a circulating toxin of fetal origin was postulated as the cause of eclampsia. More than a century later, the toxemic theory remains the favored hypothesis.