Throughout Gallagher's long history, the company has remained privately owned.
Its directors are Sir William, his brother John, and deputy chief executive Steve Tucker, who manages the agricultural side of the business. Sir William and John each have a son in the firm.
Private ownership means there are no shareholders to distract him from his first priority - customers - says Sir William, or from staff, who are second in line for his attention.
In contrast, he sees Tru-Test, Gallagher's competitor in the agriculture market, being sidetracked by its shareholders. The irony is that Gallagher, with a 19.9 per cent stake, is the biggest of those shareholders.
Gallagher makes no secret of his ambition to acquire Tru-Test, but the "spoilsport" Commerce Commission has foiled his attempts because of likely reduced competition in the electric fence market.