Spoiler alert! Reading the facts below may ruin the ending of Avenging the Queen so tread carefully.
Medieval Cologne, Germany
When I first started The Fairytale Keeper series, I envisioned Cologne as a small town with lots of farm land and a small market, but thirteenth century Cologne was a commercial city. Its location on the Rhine and position between well-traveled land routes made it a prime location for trading. Flemish cloth, wine from the Moselle region, furs, leather, gold and copper works, armor and weapons are just a few examples of goods exported from Cologne.
Archbishop Konrad von Hochstaden
Konrad von Hochstaden served as Archbishop of Cologne from 1238 to 1261. Out of all of the archbishop’s of Cologne, Konrad is one of the most famous. He was an imposing political figure during his time and a dangerous man to cross though that didn’t keep the people of Cologne from refusing to recognize his authority as soveriegn over their city. Below are a few websites that have more information about Konrad von Hochstaden.
http://en.wikipedia.org/wiki/Konrad_von_Hochstaden
http://www.newadvent.org/cathen/04258d.htm
History of The Cologne Cathedral
It was in fact burned to the ground in the 13th century though my date is off by three days for plot purposes. It was dedicated to the Virgin Mary and Saint Peter. In the year 1200, the Sarcophagi of the Three Magi was brought there and this relic made Cologne an important stop for pilgrims. For more information on Cologne Cathedral visit http://www.sacred-destinations.com/germany/cologne-cathedral
Medieval Illnesses and Plagues
Though I’ve found no evidence of a great fever in Cologne during this time, terrible illnesses ravaged cities all the time. Bubonic plague hit Europe twice. Once in the sixth century and again in the fourteenth. There is some debate about whether or not influenza existed before the sixteenth century, but illnesses called “fevers” afflicted European cities throughout history, killing many of its victims.
THE WRITER-LY WORLD OF ANDREA CEFALO 
I got onto andreacefalo.com from https://andreacefalo.com/book-one-the-fairytale-keeper/the-truth-about-13th-century-cologne/ and I
gotta say, you’ve got an attractive blog layout. How long have you been doing this? The way you do all of this makes it look like a cinch. The entire look of your page is splendid, let alone the articles.
Thank you very much for the compliment. I’ve been doing this for about a year. I pretty much just look up anything I want to know via youtube videos and rely on friends for tips on graphic design and seo.