The peak period for Nessie sightings was the 1930s, although there are several much older documents that seem to refer to this legendary creature. Based on them, the first sighting of the Loch Ness monster can be located in the 6th century, at the time of Saint Columba. According to what is told in Life of Saint Columba, when the saint was walking by the lake, he saw how they buried a man who died when he was bitten by a monster that was in the lake. As he walked through those parts, the creature launched itself to attack another man who was swimming in the lake. The saint made the sign of the cross, scolded him, and ordered him to turn around.

 The monster obeyed at the moment as if it were being pulled with ropes.

Throughout history, they have given Nessie many shapes, the most typical being the classic image of the plesiosaur. Some defined it as a kelpie, a mythological creature in the shape of a horse. In 1868, it was announced in the Inverness Courier newspaper that a fish of strange morphology and large dimensions had been seen in Loch Ness. In 1930, another newspaper, the Northern Chronicle, reported the sighting of a rare and enormous creature in the lake, which was followed by the advertisement of K. MacDonald, in 1932, who claimed to have seen an unusual crocodile in the Loch. Ness. In 1933, the Inverness Courier referred to the creature for the first time as a "monster", announcing that a couple had seen it. The following year, Arthur Grant claims monstrous to have crossed him on the road. It was here that he began to associate his image with that of a plesiosaur.