In some industries, it is necessary to adjust the history of companies after a change of name, acquisition or fragmentation, or the history of a person, e.g., after changing the employer.
To represent this, external contacts have a history relation that lets you assign a predecessor or successor to a contact.
Under Additional data/Contact relations the Successor-/predecessor history can be maintained. You can switch from the company to the predecessor company using a hyperlink, and view, for example, the activity history there.