In July 1404, Castilian ambassador Ruy González de Clavijo visited capital on a journey to Samarkand, the capital of Turco-Mongol conqueror Timur, the ruler of Iran at the time. He described it in his diary as an unwalled region.Italian traveler Pietro della Valle passed through Tehran overnight in 1618, and in his memoirs called the city Taheran. English traveler Thomas Herbert entered Tehran in 1627, and mentioned it as Tyroan. Herbert stated that the city had about 3,000 houses.