Istanbul winters are warm and wet, sum­mers hot and dry. The dimate is tempered by warm Mediterranean winds which counter frequent Black Sea cold fronts. Temperatures vary moderately between day and night as well as from season to season. The summer season is approx­imately 90 days long, while winter is 80 days long. Snow falls for an average of 7 days in a year.

The largest river in the region is the Riva , which flows into the Black Sea. In addi­tion there are two rivers flowing into the Bosphorus, Istinye Deresi and Büyük Dere. The region also boasts three small but notable lakes, all on the European shores of the Bosphorus. These are the fresh-water Terkos, which supplies the city with much of its water, and the inland seas of Küçük Çekmece and Büyük Çekmece on the Marmara coast, which are salt water lagoons. Fish are found in both these lakes, which are situated in game areas.

The city, whose population is 20 million, is a major port and trade centre. It is the most important city in Turkey, possessing a number of universities, high schools, libraries and cultural centres. The city is an impressive sight, situated, as it is, on a site dominating with the Golden Horn and the Bosphorus, and brimming with fine man uments and artefacts of the Byzantine and Ottoman era.

Up to the Turkish conquest of Istanbul by Mehmet II in 1453, the city was the centre of the Byzantine empire. After that date it became the centre of the Ottoman Empire. After the founding of the Turkish Republic in 1923, the capital of Turkey became Ankara.

EARLY SETTLEMENT AND GROWTH

Although it is not known exactly when the nucleus of the ancient city of Byzan­tine was founded there is a legend relating to the early settlement of Istan­bul. According to the legend, Byzas and his followers of Megara, near Athens, consulted the oracle of Delphi about building a new city, and were advised to build their city "opposite the land of the blind". On hearing this, the men of Megara left their country and travelled the Iong journey to IstanbuI's Seraglio Point (Sarayburnu). Looking across from this vantage point they saw the Phoenician colony of Chalcedon (Kadiköy). Astonished at the blindness of the col­onists who had failed to see the beauty of the SeragIio Point, they proclaimed Chalcedon the oracle's "city of the blind", founding their city between the Golden Horn and the point of Lygos. They nam­ed it Byzantine, after their leader. Some time later colonists from Argos also settled there  and before long Byzantine grew from a small town into an impor­tant mercantile centre, due to its strategic geographical position. The city was col­onised by the Greeks during the Hellenistic invasion in 750-550 B.C. Although its geographical position would suggest that there had been previous coloonisation on the site. Traces of settlement dating from the end of the fourth millenium to the beginning of the third millenium have been found at Fikirtepe, in Kadiköy. Archeological evidence of settlement in the 7 century B.C. was also found in the under court of Topkapi Palace, in  1937, in the form of Proto-Corinthian sherds.

We may say that the city of Byzantine began to take form during the period of Greek calanisation towards 660 B. C. Its first important histarical role was during the Persian invasions of 479 B.C. when the city was won back from the Persians by Pausanias, king of Sparta, at the batt­le of Platae. Later, the city maintained its independence in the struggle between Athens and Sparta for supremacy by bei­ng allied with the more powerful of the protagonists. From time to time the city be came extremely important, although occasionally losing its importance altogether.

The earliest city of Byzantine was sur­rounded by a wall with 27 towers. it was in the district of the present Sarayburnu, and from a topographical point of view, it was similarly placed to many cities of the same are. The walls, which stretched from Sirkeci to Ahırkapı, have left no visible trace at the present ground level. Believed to have been the most sturdy defence system of their time, the walls were of ashlar. A second wall separated the city proper from the Acropolis. The walls were believed to have been built under the guidance of Apollo and Poseidon, with a special constructional technique which provided them with amazing accoustics enabling those within to hear everything that was said on the exterior.

After the city had be en besieged by Philip of Macedonia in 340 B. C. , the walls were restored with tombstones, hence their title of Tymbosyne.

Two or three harbours were situated at Sirkeci, where the sea and land walls joined. The most important of these was Neorion (Eminönü), to the east of which was the port of Bosphorion or Prosphorion. Flanked by stone quays, these harbours were protected by towers at the mouth across which were stretehed chains.

The Acropolis, the. most sacred area of the city, was situated somewhere near the site of the present Ayasofya (the Byzan­tine cathedral of St. Sophia), and was reached via steps. Nearby was an agora surrounded by columned arcades and a statue of Helios in the centre. The arcad­ed agora was known as the Tetrastoon. The city' s water was stored in large cisterns. The largest baths in the city were the Akylleos Baths, which stood beside the Thracian Gate (Thrakion Pili). it is known that temples were built in honour of the gods and goddesses Athena, Poseidon and Zeus on the Seraglio Point, while there are traces of a shrine to Hecatairi the district of Sultanahmet ,and others to Aphrodite, Artemis and, Dionysos in and around Topkapi palace. The necropolis was outside the main walls, and stretched from Çemberlitaş to Bayezıt. Several excavations in the area yielded tombstones and mausoleums.

During the period of the Roman empire, Byzantine took the side of Pescenius Niger (193- 194) against Septimus Severus (192-211), by shutting of the road to Asia. Although Niger was defeated and killed in 194 A. D. , the city continued to resist the attacks of Septimus Severus. After a two year siege, the citizens of Byzantine, having had to resort to cannibalism in their desperation, finally surrendered. The city was severely punished, stripped of its city title and the walls demolished while soldiers and bureaucrats were put to the sword. It was a calamity for the city which later turned to its advantage. Septimus Severus soon realised the necessity of developing the city. He restored the walls and built many new buildings, restoring Byzantine to its city status. In 203 A. D. he began building a hippodrome which, however, remain­ed unfinished on his leaving the city and subsequent death. It is known that the emperor built the Zeuksippos baths bet­ween the Hagia Sofia and the hipp­odrome, a theatre on Seraglio Point, near the temple of Aphrodite and a stadium on the northern slope. He also restored several temples, namely the temples of Zeus, Aphrodite, Apollo, Artemis, Poseidon and Demeter, repaired the har­bours and constructed a grand column­ed 'via' through the city. The road was on the site of the modern Divan Yolu and stretched from the Hippodrome to the main gate in the land walls.

Severus also constructed the huge Caminia baths, which held 2000 people. The site of the baths is not certain, although they were thought to have been outside the walls. As the city grew, the Necropolis began to extend beyond Beyazıt .

During the IV century, Byzantine again became the stage of conflict during the power struggle between Constaninus Magnus (Constantine) (306-337 A.D.) and his political opponents. One of these, Licinius I (307-323 A.D.) captured Byzantine, but the city was later restored to the rule of Constantine.

The later Roman emperors felt the need to break away from Rome. Byzantine was an ideal choice as a new capital. Although close to potential enemies to the north and east, it was well fortified and easily defended, and therefore ideal from a military point of view. It was economically ideal being situated on the major trade routes between Asia and Europe, and politically attractive due to its distance from this intrigues and unrest of the old ernpire.

Constantine planned to rebuild the city and declare it the second Roman capital. Work on the construction of a new city was begun in 325 A.D. , by removing the walls further west. The new city was declared open on 11 May, 330 A. D. with great pomp and ceremony, although the construction of many buildings was to take several more years. The city was called RomaNova or Roma Secunda the new or second Rome, and possessed all the priviledges of ancient Rome. Many leading Roman families were brought to settle to aid the city's development. At first the city was ruled by a Proconsul and later by a Praefectus. By moving the walls 2 - 2.5 kms. west, Constantine enlarged the city immediately. As in Rome, it was divided into 14 administrative Regions, 12 of which were within the walls. Among those outside the walls was Galata, while the furthest district was the Blachernai, now between Edirnekapi and Ayvansaray.

The titles and functions of all the buildings in these regions were recorded in a docu­ment dating to the V century, from which we learn of the existance of large numbers of private palaces. At the centre of the columned way running through the city, the road opened out into an oval piazza, the Forum Constantini, in the centre of which stood the porphyry monument which today stands at Çemberlitaş.

The Grand Palace of the emperor was constructed between the Hippodrome and the Sea of Marmara" near the pre­sent Sultanahmet mosque. The hip­podrome was completed and adorned with a number of monuments and statuary, two temples being built near the Hagia Sophia devoted to Rhea and Tyche. The first Hagia Sophia and Havarion churches were also built during this period.

The task of aggrandizing the city was car­ried on during the reign of Julian (355-363 A.D.), who built a port on the Marmara. Valens developed the water supply system, building the aquaduct of Valens (Bozdoğan Kemeri). The main cistern and fountain were built at Beyazıt Nymphaeum Maximum). The city thus took on the character of a grand Roman capital, as Constantinopolis.

As the city grew and developed a number of important forums were built where much civic activity was centred. The most important of these were:

1 - The Augusteon: This was between what is now known as Ayasofya and Sultanahmet mosque. There were several statues and columns adorning the square and in the centre was a Triumphal Gate with a milliarrum - milestone monument underneath, symbolising the centre of roads leading to all the provinces of the vast Roman empire.

2 - Forum Constantini: This was in the present area of Çemberlitaş. An oval piaz­za with double arcades on several levels, it was decorated with statues, and in the centre on a porphyry column stood the figure of Constantine as Helios in the form of a gilded bronze statue. After later cracks appeared in this column, bronze clamp bands were fitted around it, giv­ing it its Turkish name - Çemberlitaş - the banded stone.

3-Forum Tauri (Piazza of the bull): Named after a commander of the guard known as Taurus, it is said that in the cen­tre of the piazza was the bronze statue of a bull. The piazza was restored by Theodosius I, and embellished by a grand bronze statue of the emperor with his hand oustretched towards the city, hence the alternative name of Forum TheodosiI ­

4- Forum Amastrianum: This was to the present neighborhood of Şehzadebaşı.

5- Forum Bovis (Piazza of the ox): named after a large statue of an ox - head which had been brought from Pergamon. The piazza was situated on the site of the present Aksaray Piazza.

6 - Forum Arcadi: Named after the emperor Arcadius (395-408 A.D.) , it is also known as the Herolophos. Probably rectangular, it had the column of Ar­cadius in the centre, the marble base of which can be seen today in situ, 100 m. from the Cerrahpaşa mosque. Among the other columns once decorating the square is the so-called Maiden's column erected for the emperor Marcianus by Ta­tianus (450-457 A.D.) and the Gothic column now on Seraglio Point.

With the addition of these piazzas and col­umned roads throughout, Constan­tinopolis took on the character of an imperial Roman city, the columned roads . providing protection from the hot sum­mer sun and winter rain.

With the rise of Christianity, the new religion gave the city a new identity, with churches being built on every corner.

After the great schism of 395 A.D. when the Roman empire was divided in two, a new era began for Constantinopolis, as it became the capital of the so-called new Rome, now known as the Byzantine empire.

During the region of Theodosius II (408-450 A.D.) the city underwent fur­ther considerable expansion; the walls were extended to the west, and the sec­tion between the Marmara Sea and  Tekfur Sarayı which survives today was built. To begin with, the new area within the city walls was not entirely built-up. Apart from a number of harbours on the Marmara of various sizes, the city had the advantage of being built on the Golden Horn, which is a harbour in itself. The largest of the harbours on the Marmara was the Langa, which later silted up.

While the main roadways were general­ly columned, auxiliary roads and streets were narrow, dark passages. Restrictions were placed on housing. Houses, which were stone, were to be built in terraces, to prevent restriction of the view from neigh bouring dwellings, and allowing for adequate ventilation. Different streets or neighbourhoods were allocated to artesans, artists and even foreign mer­chants. There were a great number of churches and monasteries. Meanwhile the Grand Palace was constantly extend­ed to cover an ever-greater area. Other private palaces were built through out the city, such as the Mangana Palace at Sarayburnu. From the XI century on­wards, imperial palaces began to be built in the district of the Blachernai, and the Grand Palace was gradually abandoned. During the XII century, there were large open spaces, fields, orchards and gardens within the city walIs. Monastries surround­ed by groves of trees dominated the hills of the city. While the monastery buildings were of wood, houses, palaces and chur­ches tended to be of stone, hence the ci­ty was much damaged by successive earthquakes, although relatively little effected by fire. The Latin siege of Constan­tinople in 1203- 1204, after which the city was captured by the IV Crusaders, wrought considerable damage to the city. Successive fires resulted in its even­tual desertion. During the 60 years of Latin rule folIowing this the city fell largely into ruin.

By 1261, when Constantinople was recaptured by Michael VIII (1261 - 1282) over half the city was burnt down. The emperor attempted to rebuild it, building new monasteries on the site of the old and re-housing the populace. Although the columned ways were not resored, the city now acquired roads lined with trees. The Bosphorus region, which had not been much settled during the earlier Byzantine are was totaly vacated.

Palaces and monasteries outside the city walls were abandoned, in preference for new monastries in the farthest corners of the city, such as Chora, Lips, Studios, Panmacharistos, Andreas and others, which were set in their own extensive land in the form of small complexes. At various times in Byzantine history a total of 485 churches and 325 monasteries and convents are known to have existed in constantinople. By the XIVand XV centuries, the city had become con­siderably impoverished, and was very sparsely populated. Until, in 1453, it was conquered by Mehmet II, after which time it became a Turkish city. During the Ot­toman period, the walls and many buildings were restored and new neighbourhoods were developed. Palaces, mosques, hans, baths and foun­tains were among the newly built monuments which served to give the city a Turkish character.

The largest Christian church in the Ott­oman capital of Istanbul, Hagia Sophia was converted, according to tradition, in­to a mosque soon after the city was taken. A palace was built on the site of the pre­sent Istanbul University (Eski Sarayı). Churches continued to be used as mos­ques through out the city. Muslims were brought from through out the 'Ottoman provinces to resettle in Istanbul, while Christians through out the empire were given freedom to practise their religion. Genoese and Venetian merchant col­onists were given guarantees of their con­tinued fights as citizens. After Mehmet II, the Ottoman throne was occupied by Bayezid II who constructed the Beyazıt mosque in the piazza of the same name. In 1509, the city was much damaged by a serious earthquake. Reconstruction took place on a grand scale with a workforce of 80,000 builders. During the reign of Selim I the Ottomans conquered Egypt, Syria and Mesopotamia.

The Ottoman sultans acquired the title of Caliph. Selim I being the first caliph.

Many moslem sacred relics were brought from Egypt to Istanbul. Including artefacts used by Muhammed the Prophet and his follower. These relics are still preserved in a section of Topkapı Palace.

The city was at its most splendid during the reign of Süleyman I. Belgrade was taken by the Ottomans, who had under­taken successful campaigns to Hungary and Vienna. The Ottoman fleet had turn­ed the Mediterranean into a Turkish lake; the greatest architect of the Ottoman period, Mimar Sinan was also a product of this era. He was to make a lasting mark on Turkish architecture. Among his ma­jor works were Şehzade mosque and Süleymaniye mosque. It was a law­making period, when the organisation of the state was formalised, and it was an age of ascendancy for art and philosophy. European travellers of the period, foreign envoys and visiting artists who experienc­ed Ottoman court life at close quarters described it in their works. From the XVII century onwards, the sultan's supremacy began to decline, political power falling into the hands of viziers and dowager sultans. Innumerous works of Baroque and Rococco inspiration in the Turkish style were produced during the XVII and XVIII centuries. Turkish rococco is known as the "Tulip Period".

Throughout the XIX century conflict and struggle were wide spread in the Ottoman dominions, which were spread over three continents. The Balkans were struggling for independence, while Russia was in search of access to the sea and ways of dominating the Balkans. The English and French, meanwhile, were not on pro­tecting their interests in the Near East. By the end of the century, the Ottoman em­pire was powerless in Europe. By 1912 the Bulgarians were at the gates of Istan­bul and in two years time World War I had begun. Istanbul was under British and French occupation in 1918 and the Ottoman caliphled of the coutry in 1922. In 1923 the Turkish Republic was found­ed and Mustafa Kemal Atatürk became its president, in the new capital of Ankara.