[56] During the sixth and seventh centuries, the area around Thessaloniki was invaded by Avars and Slavs, who unsuccessfully laid siege to the city several times, as narrated in the Miracles of Saint Demetrius.

[58][59] In the ninth century, the Byzantine missionaries Cyril and Methodius, both natives of the city, created the first literary language of the Slavs, the Old Church Slavonic, most likely based on the Slavic dialect used in the hinterland of their hometown.

Thessaloniki passed out of Byzantine hands in 1204,[66] when Constantinople was captured by the forces of the Fourth Crusade and incorporated the city and its surrounding territories in the Kingdom of Thessalonica[67] — which then became the largest vassal of the Latin Empire.

In exchange for his support, in the Treaty of Gallipoli the Byzantine emperor secured the return of Thessalonica, part of its hinterland, the Chalcidice peninsula, and the coastal region between the rivers Strymon and Pineios.

Thessaloniki was also the centre of activities of the Young Turks, a political reform movement, which goal was to replace the Ottoman Empire's absolute monarchy with a constitutional government.

[142] During World War II Thessaloniki was heavily bombarded by Fascist Italy (with 232 people dead, 871 wounded and over 800 buildings damaged or destroyed in November 1940 alone),[144] and, the Italians having failed in their invasion of Greece, it fell to the forces of Nazi Germany on 8 April 1941[145] and went under German occupation.

[citation needed] It is customary every year for the Prime Minister of Greece to announce his administration's policies on a number of issues, such as the economy, at the opening night of the Thessaloniki International Fair.

Architects who designed some of the most notable buildings of the city, in the late 19th and early 20th century, include Vitaliano Poselli, Pietro Arrigoni, Xenophon Paionidis, Salvatore Poselli, Leonardo Gennari, Eli Modiano, Moshé Jacques, Joseph Pleyber, Frederic Charnot, Ernst Ziller, Max Rubens, Filimon Paionidis, Dimitris Andronikos, Levi Ernst, Angelos Siagas, Alexandros Tzonis and more, using mainly the styles of Eclecticism, Art Nouveau and Neobaroque.

[108] It destroyed the city's historic centre and a large part of its architectural heritage, but paved the way for modern development featuring wider diagonal avenues and monumental squares.

In the Municipality of Thessaloniki, in addition to the historic centre and the Upper Town, are included the following districts: Xirokrini, Dikastiria (Courts), Ichthioskala, Palaios Stathmos, Lachanokipoi, Behtsinari, Panagia Faneromeni, Doxa, Saranta Ekklisies, Evangelistria, Triandria, Agia Triada-Faliro, Ippokrateio, Charilaou, Analipsi, Depot and Toumba.

[204][205] Other districts of the wider urban area of Thessaloniki are Ampelokipi, Eleftherio – Kordelio, Menemeni, Evosmos, Ilioupoli, Stavroupoli, Nikopoli, Neapoli, Polichni, Paeglos, Meteora, Agios Pavlos, Kalamaria, Pylaia and the Sykies.

The area is home to the Macedonia InterCity Bus Terminal (KTEL), the Thessaloniki railway station, and the Zeitenlik Allied memorial military cemetery.

[212] There are built the Northern Greece Naval Command and the old royal palace (called Palataki), located on the most westerly point of Mikro Emvolo cape.

[216] Part of the plan has been implemented with extensive pedestrianisations within the city centre by the municipality of Thessaloniki and the revitalisation the eastern urban waterfront/promenade, Νέα Παραλία (Néa Paralía, lit.

However, Thessaloniki still remains a major business hub in the Balkans and Greece, with a number of important Greek companies headquartered in the city, such as the Hellenic Vehicle Industry (ELVO), Namco, Astra Airlines, Ellinair, Pyramis and MLS Multimedia, which introduced the first Greek-built smartphone in 2012.

Many French and especially Italian Jews (from Livorno and other cities), influential in introducing new methods of education and developing new schools and intellectual environments for the Jewish population, were established in Thessaloniki.

"[248] In 1943, the Nazis began brutal actions against the historic Jewish population in Thessaloniki, forcing them into a ghetto near the railroad lines and beginning deportation to concentration and labor camps.

[258] The title of the European Capital of Culture in 1997 saw the birth of the city's first opera[259] and today forms an independent section of the National Theatre of Northern Greece.

The city also has a number of multiplex cinemas in major shopping malls in the suburbs, most notably in Mediterranean Cosmos, the largest retail and entertainment development in the Balkans.

The Nea Paralia parks are used throughout the year for a variety of events, while they open up to the Thessaloniki waterfront, which is lined up with several cafés and bars; and during summer is full of Thessalonians enjoying their long evening walks (referred to as "volta" or “kafès” and is embedded into the culture of the city).

[266] Other recreation spaces throughout the Thessaloniki metropolitan area include the Fragma Thermis, a landscaped parkland near Thermi and the Delta wetlands west of the city centre; while urban beaches of Peréa, Nea Mihaniona and Ayia Triada, continuously awarded with the Blue Flag beach award,[267] are located along the 10 km (6 mi) coastline of Thessaloniki's southeastern suburbs of Thermaikos gulf, about 20 km (12 mi) away from the city centre.

[287][288] Ancient Thessaloniki's Decumanus Maximus was also found and 75 metres (246 ft) of the marble-paved and column-lined road were unearthed along with shops, other buildings, and plumbing, prompting one scholar to describe the discovery as "the Byzantine Pompeii".

[297] The Dimitria festival, founded in 1966 and named after the city's patron saint of St. Demetrius, has focused on a wide range of events including music, theatre, dance, local happenings, and exhibitions.

Sports Arena in the Urban area of Kalamarià, home of the omonymous basketball team and venue of numerous music concerts, events and festivals, as well the YMCA (Youth Men’s Christian Association) indoor hall.

Coffee is an inseparable part of Thessalonians, marking a quick break from work, a socialising opportunity among friends, family and couples as well as a chance of studying, meeting new people and relax oneself.

The service is operated using Siemens Desiro EMU trains on a modernised electrified double track and stops at 11 restructured rail stations, covering the journey in 1 hour and 33 minutes.

[344] Furthermore, additional line has also been established, although with the use of regional trains, between Thessaloniki the city of Edessa home of the famous waterfalls and therapeutic thermal springs, and eventually the city of Florina, situated in the Northwestern front right bellow the foothills of Pindos Mountain chains, Florina is home to numerous ski and alpine resorts, protected national parks of relatively high natural value (Natural Habitat of Brown Bear Ursus arctos ).

namely; Sofia, Belgrade, Skopje, Vienna, Budapest, Bucharest, Istanbul and most importantly diverse German cities.Due to the Greek economic crisis, all international train links from the city were suspended in February 2011.

To tackle this problem, the government has introduced large scale redevelopment plans throughout 2011[353] with tenders expected to be announced within early 2012;[353] that include the total restructuring of the A16 in the western side of the city, with new junctions and new emergency lanes throughout the whole length of the motorway.

Preliminary plans have been announced which include a 4.5 km (3 mi) bridge over the gulf, as part of the southern bypass of the city; to cater for the large number of travellers from Macedonia and the rest of Greece heading to the airport, and to the increasingly popular tourist region of Chalkidiki.