In 1657, octroi was imposed in larger Danish cities which changed the layout and face of Aarhus over the following decades.Wooden city walls were erected to prevent smuggling, with gates and toll booths on the major thoroughfares, Mejlgade and Studsgade.As the industrial revolution took hold, the city grew to become the second-largest in the country by the 20th century.
The city gates funnelled most traffic through a few streets where merchant quarters were built.In the 17th century, Aarhus entered a period of recession as it suffered blockades and bombardments during the Swedish wars and trade was dampened by the preferential treatment of the capital by the state.In the 900s an earth rampart for the defence of the early city was constructed, encircling the settlement, much like the defence structures found at Viking ring fortresses elsewhere.The rampart was later reinforced by Harald Bluetooth, and together with the town's geographical placement, this suggests that Aros was an important trade and military centre.Market town privileges were granted in 1441, but growth stagnated in the 17th century as the city suffered blockades and bombardments during the Swedish Wars.
In the 19th century it was occupied twice by German troops during the Schleswig Wars but avoided destruction.
The charter is the first official recognition of the town as a regional power and is by some considered Aarhus' birth certificate.
The official and religious status spurred growth so in 1477 the defensive earthen ramparts, ringing the town since the Viking age, were abandoned to accommodate expansion.
In 2010, the city council voted to change the name from "Århus" to "Aarhus" in order to strengthen the international profile of the city. Certain geographically affiliated names have been updated to reflect the name of the city, such as the Aarhus River, changed from "Århus Å" to "Aarhus Å".
It is still grammatically correct to write geographical names with the letter Å and local councils are allowed to use the Aa spelling as an alternative.
Some Danish cities resisted the new spelling of their names, notably Aalborg and Aabenraa.