South Holland ( ) is a province of the Netherlands with a population of over 3.7 million as of October 2021 and a population density of about , making it the country's most populous province and one of the world's most densely populated areas. Situated on the North Sea in the west of the Netherlands, South Holland covers an area of , of which is water. It borders North Holland to the north, Utrecht and Gelderland to the east, and North Brabant and Zeeland to the south. The provincial capital is the Dutch seat of government The Hague, while its largest city is Rotterdam. The Rhine-Meuse-Scheldt delta drains through South Holland into the North Sea. Europe's busiest seaport, the Port of Rotterdam, is located in South Holland. History Early history Archaeological discoveries in Hardinxveld-Giessendam indicate that the area of South Holland has been inhabited since at least c. 7,500 years before present, probably by nomadic hunter-gatherers. Agriculture and permanent settlements probably originated around 2,000 years later, based on excavations near Vlaardingen. In the classical antiquity, South Holland was part of the Roman Province of Germania Inferior, and the border of the Roman Empire ran along the Old Rhine and reached the North Sea near Katwijk. The Romans built fortresses along the border, such as Praetorium Agrippinae near modern-day Valkenburg, Matilo near modern-day Leiden, and Albaniana near modern-day Alphen aan den Rijn. A city was founded near modern-day Voorburg, Forum Hadriani. It was built according to the grid plan, and facilitated a square, a court, a bathhouse and several temples. After the departure of the Romans, the area belonged to the Frisian Kingdom, after which it was conquered by the Frankish king Dagobert I in 636. In 690, the Anglo-Saxon monk Willibrord arrived near Katwijk and was granted permission to spread Roman Catholicism by the Frankish king Pepin II. He accordingly founded a church in Oegstgeest, after which the entire area was gradually Christianised. The area was appointed to East Francia in the Treaty of Verdun in 843, after which the king granted lands to Gerolf, who had helped him claim the lands. This was the birth of the County of Holland. Gerolf was later succeeded by Dirk I, who continued to rule Holland under the Frankish king. In 1248, count William II ordered the construction of the Ridderzaal, which was later finished by his son and successor Floris V. The