Pernod Ricard, the world’s second-biggest alcoholic-beverage company, was once considered safe from the claws of activist investors.

Not only was it one of France’s oldest businesses, tracing its roots back to 1805 — when Henri-Louis Pernod set up an absinthe distillery in the small town of Couvet — but it also had the implicit protection of the Ricard family, its largest shareholder.