The area that is now known as Cologne was originally inhabited by a Germanic tribe called the Eburones, but they were destroyed by Julius Caesar and his army in about 53 BC, and his Roman general Agrippa colonized it with another tribe, the Ubii. A fortified settlement was founded on the site in 38 BC, and in15 BC, Julia Agrinnina, who would grow up to marry the Emperor Claudius and become the mother of Nero.
In 50 AD, a Roman colony, Colonia Claudia Ara Agrippinensium was founded. The colony, which was generally called simply Colonia, was designated to be headquarters of the governor of Lower Germany. The Franks conquered the Colonia in the fifth century and became part of the Frankish Kingdom.
In the second century, a Christian community flourished in Cologne, and in 313, it was first mentioned as a bishopric. Near the end of the eighth century, Charlemagne declared it an archbishopric. By the tenth century the city was bustling with trade and industry, and the archbishop was getting tolls, custom duties, and all sorts of other payments. Conflicts began to come up between the wealthy merchants who wanted both political and and commercial liberty and the archbishop who enjoyed the perqs of his position. In the thirteenth century, the job of elector was added to the duties of the archbishop. An elector was a man who had a part in the election of the German king, called the emperor.
In 1288, the Battle of Worringen saw the archbishop defeated, and Cologne became self-governing. Although the city was a de facto free imperial city at that time, it would not be officially recognized as such until 1475. In 1396, a nonviolent revolution changed everything. a new constitution was instituted and the guilds became the government since they elected the council which had power over both internal and external concerns.
Cologne continued to flourish, as did the merchants and the guild. Textile manufacturing, metalworking, enameling, bookmaking, leatherworking, and goldsmithing kept the economy rolling. But all that changed after the Thirty Years' War (1618-48), when the city began to decline. In 1794, France conquered the city, after which Prussia took power, and the new age of prosperity began. A chamber of commerce was established and industry grew quickly. The population ballooned from 41,685 in 1801 to 372,529 by the end of the century.
The outbreak of the First World War stopped the growth, and it wasn't until 1933 that the growth and prosperity returned. In March of that year, local elections installed the Nazi Party winning, and literally the next day, Nazis occupied city hall and took over the government. They imprisoned Communist and Social Democratic members of the city assembly, and the Mayor, Konrad Adenauer, was ejected from his office. When the Nazis first took power, 20,000 Jews lived in the city, and by 1939, more than 40% of them had emigrated out. Almost all of those who remained were eventually deported to concentration camps.
In 1939, there were 768,352 residents in Cologne. The Allies engaged in 262 air raids of the city, Cologne suffered 20,000 casualties, and the city was destroyed. Almost every home was damaged, and 91 of the 150 churches were razed.
By March of 1945, the population was down to 40,000. By the end of the year, however, the population was back up to 450,000, with more people moving to Cologne, even as reconstruction was embarked upon. All the while, the city was shifting away from industry and toward technology, and since then, Cologne has retaken its place as the cultural and economic center of northwestern Germany.
 
 
Recommended Resources
The Hohe Domkirche Sankt Petrus, in English, the Cathederal Church of Saint Peter, is the seat of the Archbishop of Cologne is the subject of this site. The history of the cathedral, the construction of which was begun in 1248 and finished around 1304, begins long before the building was there, and the site takes us back to the 4th century. There is quite bit of information about the architecture, the sculptures, and the stained glass.
http://colognecathedral.net
Provides descriptions and photographs of the rooms as well as the suites and a frequently updated section which lists and describes all of the packages being offered. The breakfast buffet, offered to all guests, is discussed here, and a list of food items which are offered, including cereals, eggs, cold cuts, numerous cheeses, and pastries. It is also easy to book a room from any page on the website.
http://www.senats-hotel.de/homepage-english/
The official Tourist Board website takes the reader on a virtual tour of Cologne, starting with attractions and cultural events, from museums to the opera and of course, the Romanesque churches. The food and drink section cals attention to restaurants and cafes and has an entire weblog about the nightclubs in the city. And to top it all off, there is a section outlining what to expect on a visit to the Chocolate Museum.
https://www.cologne-tourism.com