As a cognomen , it was applied to Romulus , the legendary founder and first King of Rome .
It was later applied to other persons , including a family of the Sulpicia gens , and deities , including Mars , Janus , and the deified Augustus .
As a cognomen , it was applied to Romulus , the legendary founder and first King of Rome , and it was later applied to other persons , including a family of the Sulpicia gens , and deities , including Mars , Janus , and the deified Augustus .