Short answers, pulled from the story.
Romulus regulated the patronage relationship as one of his earliest concerns at the very founding of the city. Greek historians Dionysius and Plutarch dated this system to the beginning of Roman history.
The Latin word for father connects both patrician and patronus, indicating a patriarchal nature within Roman society. This linguistic link highlights the family-like structure of the social bond between individuals.
Requests were usually made by clientela at a daily morning reception known as the salutio. The patron received his clients at dawn in the atrium and tablinum before escorting them to the forum.
Traditional clientela began to lose its importance as a social institution during the 2nd century BC. Terms such as patronus, cliens, and patrocinium were used in a more restricted sense compared to amicitia or hospitium.
When a slave was manumitted, the former owner became their patron. The freedman had specific social obligations involving campaigning on behalf of the patron if they ran for election.