year of foundation
The calendar year in which a company or organization begins to exist as an active entity.
The year of foundation is the calendar year in which a company or other organization begins its existence as an active entity capable of functioning in its defined role. It may also refer to an organization's commencement of existence in a new form which is built on other preexisting organizations. It does not refer to the event of a name change or any superficial commencement of existence.
The event is the beginning of an active organization capable of doing its work. A new form built on a predecessor can have its own commencement even when some people or activities continue from the predecessor.
A change of name alone is not such a commencement. The year identifies the start of the active entity described above, rather than every later change to its name or premises.