Beginning

noun

1. The act of doing that which begins anything; commencement of an action, state, or space of time; entrance into being or upon a course; the first act, effort, or state of a succession of acts or states.
2. That which is begun; a rudiment or element.
3. That which begins or originates something; the source or first cause.

   "What was the beginning of the dispute?"

4. The initial portion of some extended thing.

   "That house is at the beginning of the street."