Institutionally, Ottoman sultans were sending agents or envoys to carry out their specific missions in the ad hoc diplomacy period. Although they did not establish permanent embassies in foreign states before the 18th century, the Ottomans allowed foreign states to establish diplomatic missions in the empire. Venice was the first state opened an embassy in Istanbul right after the conquest. It was followed by Poland (1475), Russia (1497), France (1525), Austria (1528), the Great Britain (1583) and the Netherlands (1612).