A marshy area, the Romans decided to build 2 main roads leading out of Lutetia. In the 6th century, the marshes were drained and cultivated, and religious institutions developed. In the 11th century, the kings of France set up a structure for executions outside the walls on the Montfaucon mound (now the Place du Colonel Fabien): the patibular forks. Following numerous epidemics in the second half of the 16th century, Henri IV decided to build the Hôpital Saint-Louis, which was to be used to quarantine contagious patients during epidemics.
The 10th arrondissement really took off in the 18th century with the construction of the Grand Boulevards. Numerous theaters were built around the Porte Saint-Martin, a tradition that continues to this day. As Paris grew, Napoleon Bonaparte decided to canalize the Ourcq to remedy the poor drinking water supply for Parisians. The second half of the 19th century saw the launch of a major urban development project, with the creation of 2 railway stations (Gare de Strasbourg, which later became Gare de l’Est and Gare de Nord) and the construction of the Lariboisière hospital, close to the 9th arrondissement.