The theory is today accepted by the majority of New Testament scholars, who also hold that Matthew and Luke used a lost source of Jesus's sayings called Q.
Before the Enlightenment, the belief of many, including the Church Fathers (Augustine of Hippo, Jerome, Eusebius, Origen, and Irenaeus), had been that Matthew was the first gospel to be written. This traditional view of gospel origins, however, began to be challenged in the late 1700s, when Gottlob Christian Storr (1786) proposed that Mark was the first to be written.
Storr's idea met with little acceptance at the time, with most scholars favoring either Matthean priority, under the traditional Augustinian hypothesis, or the Griesbach hypothesis, or a fragmentary theory. In the fragmentary theory, it was believed that stories about Jesus were recorded in several smaller documents and notebooks and combined by the evangelists to create the synoptic gospels.
Working within the fragmentary theory, Karl Lachmann (1835) compared the synoptic gospels in pairs and noted that while Matthew frequently agreed with Mark against Luke in the order of passages and Luke agreed frequently with Mark against Matthew, Matthew and Luke rarely agreed with each other against Mark. Lachmann inferred from this that Mark best preserved a relatively fixed order of episodes in Jesus's ministry.
In 1838, two theologians, Christian Gottlob Wilke and Christian Hermann Weisse, independently extended Lachmann's reasoning to conclude that Mark not only best represented Matthew and Luke's source but also that Mark was Matthew and Luke's source. Their ideas were not immediately accepted, but Heinrich Julius Holtzmann's endorsement in 1863 of a qualified form of Markan priority won general favor and is still the dominant hypothesis today.