The founding of the city by Romulus was commemorated annually on April 21, with the festival of the Parilia. Romulus's first act was to fortify the Palatine, in the course of which he made a sacrifice to the gods. He laid out the city's boundaries with a furrow that he ploughed, performed another sacrifice, and with his followers set to work building the city itself. Romulus sought the assent of the people to become their king. With Numitor's help, he addressed them and received their approval. Romulus accepted the crown after he sacrificed and prayed to Jupiter, and after receiving favourable omens.