The gulf has been an important waterway since ancient times, bringing the people who live on its shores into early contact with other civilizations. In the ancient world, the gulf peoples established trade connections with India; in the Middle Ages, they went as far as China; and in the modern era, they became involved with the European powers that sailed into the Indian Ocean and around Southeast Asia. In the twentieth century, the discovery of massive oil deposits in the gulf made the area once again a crossroads for the modern world.