The Safavid Shah Tahmasp died in 1576, and internal dissensions in Persia only ended with the accession of Shah Abbas I in 1587 (he ruled until 1628). The mutual expansionism of the Ottomans and Safavids in the buffer-zone between their empires (mainly Iraq) led to a long war which began in 1578, and went through three main phases (1578-1590, 1603-1618 and 1623-1639) until the treaty of Qasr-i Shirin in 1639 finally fixed the border between the two empires. Both sides conquered, lost and re-conquered large areas, but the local tribes (Turkish-speaking but Shi’i) remained loyal to the Safavids, and the Ottomans were handicapped not only by the remoteness of the area in which they were fighting, meaning that their troops and supplies were moved with difficulty, but also by having to attend to their interests in the West (the Ottomans declared war with Austria in 1593, until 1605 when the Ottoman Sultan finally recognised the Habsburg emperor as his equal). Shah Abbas actually formed alliances with the Ottomans’ European enemies, and with English aid he took Hormuz from the Portuguese in 1622 and founded the port of Bander Abbas. The Ottomans retaliated by depriving Persia of valuable metals and copper which caused a severe currency crisis. The Ottoman empire was by then severely weakened by an internal crisis of the turn of the C17th, until Sultan Murad IV (1623-40) reimposed central authority (1632-35) and forced the Persians to come to terms.