Without tall mountains, Uppland was one of the last Swedish provinces (landskap) to rise from the Baltic Sea after the Ice Age. Still in 1,500 BC, at the beginning of the Iron Age, most of today's land surface was below sea level.
Around AD 1000 the kingdom of Sweden was founded with Sigtuna as its first capital, and as its religion. As Sigtuna was sacked by pirates in 1187, Stockholm was founded to protect Mälaren, and later became the national capital. Uppsala was the site of a pagan temple, which was torn down in the late 11th century, as Christianity arrived. A century later, the city became the seat of the Church of Sweden.
From the Middle Ages, Uppland was an international forerunner in metallurgy. In the early 17th century, blacksmiths from Wallonia founded several workshops around Östhammar, and forged weapons which were used to establish the Swedish Empire (see Nordic history).
Since the Industrial Revolution, Stockholm and Uppsala have grown, while the minor towns now function as extended suburbs of these cities. With nearly 1.5 million inhabitants, Uppland is Sweden's most populous province.
Though Swedish provinces are usually the foundation of folk culture and local patriotism, Uppland lacks a unifying identity, and very few inhabitants think of themselves as "Upplanders". Today, the province is much characterized by the gap between the bustle of Stockholm and Uppsala, and the quiet northern forests.