children and resident foreigners. An estimate based on Thucydides is 40,000 male citizens, 100,000 family members, 70,000 metics (resident foreigners) and 150,000-400,000 slaves, though modern historians again hesitate to take such high numbers at face value, most estimates now preferring a total in the 200–350,000 range. The urban area of Athens proper (excluding the port of Piraeus) covered less than a thousandth of the area of the city-state, though its population density was of course far higher: modern estimates for the population of the built-up area tend to indicate around 35–45,000 inhabitants, though density of occupation, household size and whether there was a significant suburban population beyond the walls remain uncertain. The ancient site of the main city is centred on the rocky hill of the acropolis. Many towns existed in the Athenian territory. Acharnae, Afidnes, Cytherus, Colonus, Corydallus, Cropia, Decelea, Euonymos, Vravron among others were important towns in the Athenian countryside. The new port of Piraeus was located in the site between the passenger section of the modern port (named Kantharos in antiquity) and Pasalimani harbour (named Zea in antiquity). The old port (Phaliro) was in the site of modern Palaio Faliro and gradually declined after the construction of the new port, but remained as a minor port and important settlement with historic significance in late Classical times. Modern Expansion The rapid expansion of the modern city, which continues to this day, took off with industrial growth in the 1950s and 1960s. The expansion is now particularly toward the East and North East (a tendency greatly related to the new Eleftherios Venizelos International Airport and the Attiki Odos, the freeway that cuts across Attica). By this process Athens has engulfed many former suburbs and villages in Attica, and continues to do so. The table below shows the historical population of Athens in recent times. The metropolitan population reached a peak around 2006 and since then has stabilised and even dropped slightly at around 3.7 million. Government and politics Athens became the capital of Greece in 1834, following Nafplion, which was the provisional capital from 1829. The municipality (City) of Athens is also the capital of the Attica region. The term Athens can refer either to the Municipality of Athens, to Greater Athens or urban area, or to the entire Athens Metropolitan Area. International relations and influence Twin towns – sister cities Athens is twinned with: Partnerships Belgrade, Serbia (1966)