A native Frenchman, Sengle, then Bailli of the French langue of the Order, was heavily involved in the battles of the Knights in the Mediterranean and in North Africa against the Ottoman corsairs led by admiral Turgut Reis, and particularly in the struggles for Djerba and Tripoli.

Sengle had considerable impact on the military strengthening of Malta, notably by initiating in 1554 the development of the city of Senglea, which was later named after him and uses his coat of arms.

Therefore, Charles V ordered the Viceroy of Sicily, Juan de Vega, to destroy it to prevent Muslim occupation.

[2] Vega did burn Mehdia, but he retaliated against Malta for not accepting the city and prohibited exportation of wheat to the island.

In 1557, Prior François de Lorena commanded five of the Order's galleys and they engaged a Muslim fleet off Rhodes.