When the Ice Age was over and the glaciers receded, the whole landscape around Bled was shaped by the Bohinj glacier in Pleistocene. The valley in which lake Bled lies was formed by tectonic activity. During the erosion period softer ground was worn away, but the more resistant top soils around the edge of the lake remained. The most typical of these are the castle rock and the island. There are thermal water springs in the north-eastern part of the lake. Nineteen different fishes thrive in the waters of the lake.
The first but rare traces of human beings at Bled originate in the Bronze Age. In the Iron Age, when iron began to be available in Alpine settlements, the population became more dense.
The first wave of Old-Slavic setlers arrived in Bled in the 7 century. The most typical objects found in the graves from this period are ear-rings in the shape of a basket, painted ear-rings and brooches in the form of a peacock (on view in the Castle museum).
After the period of the Old-Slavic state, Bled came first under Frankish rule (Charlemagne 782) and afterwards under German rule. In 1004, the German Emperor Henry II gave Bled with the territory between the two Savas, and in 1011 the Castle, to Bishop Albuin of Brixen. The holders of the Castle were knights in bondage who, in the name of the Bishops of Brixen, upheld the feudal power. Because of the encroachment upon the rights of serfs and their maltreatment, in 1510 the peasants of Bled joined the fight for the "old justice" in the general Slavic insurrection and destroyed Bled Castle.
In 1558 a new holder, Herbert VII of Auersperg, took over the Castle. He was a great defender of the Protestant faith, which was rapidly spreading in Bled in this period. After 800 years of the rule of Bishops of Brixen, with the abolition of bondage, the dominion of Bled lost its character as a feudal, economic and social unit. The revenues diminished and in 1858 the Bishops of Brixen sold it to the commoner Viktor Ruard, proprietor of the iron-works in Jesenice. In 1919 the Castle with the lake was bought by the hotel keeper Ivan Kenda from Bled. In 1937 the property was taken over by the Associated Commercial Bank and finally by the former District of Drava. So the great times of Bled Castle had passed; the Castle alone bears witnes to Bled's former splendour, removed from the tumult of the valley, which used to be its property and which has now developed into a holiday centre.
With the construction of Vienna-Ljubljana-Trieste southern railway (1849-57), Bled especially developed health-resort tourism. The well-known in "Pri Mallnerju" was opened, and in 1853 a more solid bathing-house for the thermal springs was built. The beginnings of more intensive tourism at Bled originate in 1855 when the Swiss doctor of hygiene Arnold Rikli was among the first to see the value and the advantages of the climatic conditions as well as the very favourable location of Bled for a long bathing season. With the motto: "The water, of course, is useful, but the air does even better and the light best of all" he established in Bled his well-known solar, air and thermal baths, built simple dwellings and began to cure his patients. For fifty years Rikli worked at Bled and the place changed thoroughly. Besides Rikli's patients, Bled attacted more and more guests who wanted to spend their holidays in a healthy and, above, all beautiful environment. After the year 1870, with the construction of Tarvisio-Ljubljana railway line, Bled acquired its own railway station at Lesce, where numerous passenger and express trains stopped and the number of visitors to Bled therefore grew constantly. In 1903, on the occasion of the great international exhibition of health-resorts in Vienna, Bled won a gold medal, and in 1906, Bled was offically ranked among the important tourist centres of Imperial Austria. In the second half of the 19th century Bled changed considerably. The typical Carniolian villages around the lake, which from the Middle Ages on were closed units, fused together. They were linked by villas and hotels and connected by colourful parks. The new united settlement offically took over the name of Bled.