The History of the Königsallee

The boulevard was designed by Caspar Anton Huschberger when the area was redeveloped in 1802, and built to replace pre-existing fortifications.
It was completed in 1804.

In 1812 Breidenbacher Hof was openend.
The canal which runs through the center of the boulevard is 31 m (102 ft) wide and 5 m (16 ft) deep. The canal is fed by the Düssel, which was diverted to provide the nececessary water. Two wooden bridges cross the canal. On the suggestion of the landscape architect Maximilian Friedrich Weyhe, trees were planted along the boulevard and the boulevard was given the name "Kastanienallee" ("Chestnut Avenue").

After an incident in 1848, when horse manure was thrown at King Friedrich Wilhelm IV, the road was renamed "Königsallee" ("King's Avenue") as a gesture of goodwill.

(Wikipedia - The Free Enzyclopedia)