In 1840, Youssef aged 17 years, fought alongside his father and elder brother against the Egyptian armies then occupying Lebanon in the battles of Houna and Bazoun. Youssef showed remarkable skill as a warrior and leader, and his reputation and influence in the area steadily grew; so much so that in 1846, when his father died, Youssef succeeded him as ruler instead of his elder brother. Youssef ruled with fairness, and his credibility and influence as a soldier and politician continued to grow.