Istanbulİstanbul

The site was settled by Greek colonists in the seventh century BCE, who called it Byzantion. It was a small trading city on a triangular promontory where the Bosphorus meets the Sea of Marmara and the Golden Horn, an easy place to defend and a natural toll gate on the route between the Black Sea and the Mediterranean. Rome absorbed it, and in 330 CE the emperor Constantine chose it as the seat of the eastern empire and renamed it after himself. Constantinople grew fast, and the Hippodrome, the great cisterns and the land walls that still mark the west of the old city all date from the centuries when it was the largest city in Europe.

For a thousand years it survived sieges, fires, riots and one disastrous sack by the Fourth Crusade in 1204. Emperor Justinian rebuilt the centre after the Nika riots of 532, and his church of Hagia Sophia, finished in 537, stayed the largest cathedral in the world for almost a thousand years. In 1453 the Ottoman sultan Mehmed II took the city after a siege and made it his capital. He converted Hagia Sophia into a mosque, repopulated the city with people from across his lands, and built the first palace on the hill above the Golden Horn. His successors turned Constantinople into a capital of the Islamic world with mosques, schools, hospitals and markets; Süleyman the Magnificent's reign in the sixteenth century is often seen as its height.

The last two centuries were a long unwinding. The Ottoman state lost territory, modernised its army and its buildings, and built palaces along the Bosphorus in a European style. After the First World War the empire ended, the Republic was declared in 1923 under Mustafa Kemal Atatürk, and Ankara replaced Istanbul as the capital. The city stayed the country's commercial and cultural centre and grew from under a million people in the 1950s to a metropolis of many millions today. Two bridges, then a third, a metro under the strait and a new airport have all been added within living memory. A visitor sees all of this at once: a sixth-century dome, a sixteenth-century mosque and a twenty-first-century tram within the same square.

Istanbul reads best as a set of hills and shores. The old peninsula between the Golden Horn and the Sea of Marmara is where Byzantium began, and its names still describe the layers: Sultanahmet for the imperial core, Topkapı and Gülhane for the palace and its parkland, Eminönü and Sirkeci for the harbour and the old railway terminus. Walk from the square in front of Hagia Sophia down to the water and you cross the whole story from church to palace to port in twenty minutes, on a slope that explains why the Ottomans placed their court on the high ground and their markets at the quay.

Across the Golden Horn the character changes. Galata was a walled Genoese colony from the thirteenth century, a foreign-run trading quarter with its own tower, and it kept a mix of Greeks, Armenians, Jews and Levantine merchants until the twentieth century. Karaköy below it was the banking and shipping district, and it is now full of cafés and small galleries in old commercial buildings. Above it, Beyoğlu and İstiklal Avenue grew in the nineteenth century as the European quarter, with embassies, theatres, arcades and apartment blocks in a style borrowed from Paris and Vienna. The steepness of the hill is real: the Tünel funicular, opened in 1875, was built to save people from the climb and is one of the oldest underground railways in the world.

Further out, the quarters are more local. Balat and Fener on the Golden Horn were Jewish and Greek Orthodox neighbourhoods with painted wooden houses and a few small churches, now being renovated and getting cafés. Kadıköy and Üsküdar on the Asian shore have the market streets, the fish stalls and the tea gardens that residents actually use. A first visit needs the old peninsula and the hill; a second visit rewards a ferry ride and a slow afternoon on the other side. Each district works best on foot, with a ferry or tram between them rather than a taxi through traffic.

The skyline is a lesson in domes. Hagia Sophia is the first big statement: a dome about 31 metres across seemingly floating over a square nave on windows and pendentives, built in under six years by two mathematicians, Anthemius and Isidore. The Ottomans took that idea and made it a national language. Their greatest architect, Mimar Sinan, served four sultans in the sixteenth century, and his Süleymaniye Mosque above the Golden Horn balances a central dome with half-domes and slender minarets in a way that answers, and arguably improves on, the Byzantine model. Sinan is credited with hundreds of buildings across the empire, including mosques, bridges, baths and schools.

The Blue Mosque, built for Sultan Ahmed I between 1609 and 1616, is the last of the great imperial mosques of the classical period and stands opposite Hagia Sophia on the same square. It has six minarets, which, the story goes, caused a small scandal at the time because the Great Mosque of Mecca had the same number, and the sultan is said to have solved it by funding a seventh minaret in Mecca. Inside, tens of thousands of blue İznik tiles give it the name that visitors use, while its official name is Sultanahmet Mosque. Topkapı Palace tells the other Ottoman story: not a single monument but a series of courtyards, kiosks and chambers in which the court lived, with a Harem, a treasury and pavilions that look over the Bosphorus.

Underground, the Basilica Cistern shows what the Byzantine city did for water: 336 columns hold a vaulted roof over a reservoir that supplied the imperial palace. On the north bank the Galata Tower is a stone cylinder dating from the fourteenth century in its current form, and the nineteenth-century palaces along the Bosphorus, Dolmabahçe above all, show the empire in its late European style. The everyday city is architecture too: wooden houses that survived the fires, Art Nouveau apartment blocks in Beyoğlu, and the long stairs that connect the levels of the hill. Look up at a roofline and you often see three centuries at once.

Turkish cooking grew from the Ottoman court kitchen, and the palace kitchens at Topkapı fed thousands of people each day. Court cooks combined Central Asian traditions of meat, yogurt and flatbread with Persian, Arab, Balkan and Mediterranean ingredients that arrived along the empire's roads. Olive oil dishes served cold, stuffed vegetables, pilafs, slow lamb stews and syrupy sweets all spread from that mix. Because the city drew people from every province, its restaurants and home kitchens kept regional dishes from the Aegean, the Black Sea, the south-east and the Balkans, which is why one street can offer several regional cuisines.

The day is organised around a few habits. Breakfast, kahvaltı, is a spread of white cheese, olives, tomatoes, cucumbers, eggs, honey, clotted cream and jam, eaten slowly with tea, and weekend brunch at a good breakfast house is a social event. Lunch is often a lokanta, a plain restaurant with a steam counter of vegetable dishes and grills, or a quick köfte or döner. Simit, the sesame ring, and tea are the street snack. On the water the fish sandwich, balık ekmek, became a symbol of the Golden Horn in the twentieth century. Dinner might be a meyhane, a tavern where small cold dishes called meze arrive in a long series alongside rakı, the aniseed spirit, diluted with water until it turns cloudy.

Sweets have a long history in the city. Baklava reached its modern form in the palace kitchens, and a tradition holds that the sultans' guards received a tray of it in a procession in the middle of Ramadan. Turkish delight, lokum, was sold in shops from the eighteenth century, and coffee arrived in the sixteenth century, when the first coffeehouses opened near the palace and were promptly regulated because people talked politics in them. Tea overtook coffee in the twentieth century as the everyday drink, served in small tulip glasses. For a visitor the practical lesson is to eat according to the hour: breakfast late, fish at the water, baklava in the afternoon and dinner late, rather than trying to fit everything into one meal.

Istanbul is unusual among big cities in how much of its daily life still runs across water. The Bosphorus is a strait about 30 kilometres long that connects the Black Sea to the Sea of Marmara, and it is one of the busiest waterways in the world, carrying ships of every kind close enough to the shore that residents watch tankers from their kitchens. The Golden Horn, a drowned river valley about seven kilometres long, gave the old city a sheltered harbour, and the chain that once closed its mouth against attackers appears in every account of the siege of 1453. The two cities on either side, Europe and Asia, are joined by bridges, a tunnel and a rail link under the seabed, but most commuters who live on one side and work on the other still take a ferry.

The public ferry system dates from the mid-nineteenth century, when steamers began to replace rowing boats between the shores, and the name Şirket-i Hayriye, the Good Enterprise Company, is still on some of the older vessels. Today the ferries carry millions of passengers a year on routes to Kadıköy, Üsküdar, the Bosphorus villages and the Princes' Islands. A crossing is cheap, the fare is on the same card as the tram, and the outer deck is the best view in the city: the old peninsula's domes on one side, the Asian hills on the other, and gulls that will take a simit from your hand. Locals feed them from the stern and drink tea in the cabin.

For planning, the water matters in three ways. The first is time: a crossing by ferry is usually faster and less stressful than a taxi in traffic. The second is light: the best views of the skyline are from the water in the last hour before sunset. The third is weather: strong wind or fog can cancel ferries, and winter storms can change the timetable, so a second option by tram or Marmaray is a sensible backup. A ride to Kadıköy for lunch and a return at dusk is one of the best days you can build with a single card and no tour. The Princes' Islands are the longer version, with pine lanes, horse carriages and bicycles on car-free islands.

Istanbul is a Muslim-majority city with a long tradition of mixing communities. The prayer call, the ezan, sounds five times a day from thousands of minarets, and the times shift through the year with the sun. Friday is the main congregation day, when mosques fill around midday and traffic near the biggest ones slows. For a visitor the practical consequences are simple: mosques close to tourists during prayer and on Friday mornings, dress is modest, and shoes come off at the door. Beyond the mosques, the city has Greek Orthodox, Armenian, Jewish and Catholic churches and synagogues, some of them centuries old, and several of them welcome visitors at set hours.

The calendar has two layers. The civil year has public holidays such as 23 April, Children's Day, 29 October, Republic Day, and 30 August, Victory Day. The religious year follows the Islamic lunar calendar, so its dates move about eleven days earlier each year. Ramadan is a month of fasting from dawn to sunset, ended by Ramazan Bayramı, a three-day holiday of family visits, sweets and closed shops. Kurban Bayramı, the feast of sacrifice, comes about two months and ten days later and is the longest holiday of the year, when many residents leave the city and long-distance transport is booked out. If your dates fall near one, book beds and transport early and expect shorter hours.

The daily rhythm is a good guide to how to use the city. Mornings start with tea and a simit; mid-morning is the best time for the sights; lunch is early and quick; the afternoon is when the heat and the crowds peak; and the evening, from about 19:00 to midnight, is when the city comes alive again, with the waterfront, the terraces and the meyhanes full. Shops stay open late, the ferries run until after dark, and dinner is rarely before 20:00. A visitor who follows this rhythm, with an early start, a long break and a late dinner, finds the city much easier than one who tries to do everything between ten and four.