Eight of their thirteen children survived to adulthood: Catherine, Mary, John, James, Martha, Eliza, Martin and Peter.
[1]: 4 At the age of 17, Peter de Havilland was sent to Cette on the Mediterranean coast of France, an important port for the wine trade, working with Marc Fraissinet, a local merchant with contracts to supply wines to the Dobrée and de Havilland families, to learn the trade.
He had not followed the usual path of studying French or Norman law at a university in France before setting up his legal business.
On another occasion, when the Bailiff locked the court building so that the case could not be heard, the jurats broke in, held the hearing, which was unopposed, and awarded de Havilland damages of £1,000.
In 1813 the Privy Council agreed to the pay rise, also giving increases to the court officials,[1]: 94 but faced opposition in Guernsey from those who considered the post an honorary one.
In 1814, on de Havilland's recommendation, the Privy Council gave permission for a duty (impôt) to be levied on alcohol to fund improvements on the island, again triggering opposition from local business people.
[1]: 101 In 1817 de Havilland was knighted by the Prince Regent[1]: 112 for services to Guernsey and for supporting the provision of improved military roads.