The settlement of the Portuguese at the Strait of Hormuz sparked a flourishing commerce with Europe. After the death of Shah Ismail, his 10-year-old son Shah Tahmasp came into power. In 1534, Suleiman invaded Iran with a force numbering 200,000 men and 300 pieces of artillery. Tahmasp could only field 7,000 men (of dubious loyalty) and a few cannons. The Ottomans seized the Safavid capital Tabriz, and captured Baghdad. Tahmasp avoided direct confrontation with the Ottoman army, preferring to harass it then retreat, leaving scorched earth behind him. This scorched earth policy led to the loss of 30,000 Ottoman troops as they made their way through the Zagros mountains and Suleiman decided to abandon his campaign. Twelve years of confusion followed the death of Tahmasp in 1576, and it was not until the arrival of Shah Abbas the Great that calm was restored. He quickly signed an unfavourable peace with the Ottomans, to give himself time to establish an army of "ghulams". These fully loyal converted slave soldiers of ethnic Circassian, Georgian and Armenian origin had been deported to Persia en masse since the time of Tahmasp I. Trained with the best training and equipped with the best weapons, these soldiers would replace the Qizilbash from virtually all their positions in the royal household, the civil administration and the army, and be fully loyal to the Shah. These measures, including the heavy European reforms of the army, thanks to the British brothers Shirley, allowed the Shah to easily defeat the Uzbeks and to retake Herat in 1598, then Baghdad in 1624, and the whole Caucasus, and beyond. This reign, the highlight of the dynasty, supported flourishing commerce and art, notably with the construction of the new capital of Isfahan. The period after the death of Shah Abbas was a long decline, partly due to the harem system, which encouraged intrigue and manipulation, often by the same new Caucasian layers in the Persian society. The reign of Shah Safi (reigned 1629–1642) was notable for its arbitrary violence and territorial retreats; that of Shah Abbas II marked the beginning of religious intolerance towards the Dhimmis and particularly the Jews, a situation which continued under Shah Suleiman and Shah Husayn. Disintegrated by feuds, civil strife, and foreign interference of most notably the Russians, Dutch, and Portuguese, a rebellion of Afghans would be enough in 1709 to lead the dynasty eventually to a fall in 1722.