On a runestone from the 1000s, found in Riksby ägor, one could previously read that the stone was erected in memory of the farmer Björn as byki : ulsunti i.e. byggi in Ulvsundi/lived in Ulvsund.
The castle and its garden were bought by the Stockholm County Council, which for a long time used it as a nursing home.
In 1906, he joined forces with Per August Kindgren, a former horse tram driver and the former owner of Lillsjönäs farm.
In 1919, among other things, the Ulvsunda fire and police station (closed in 1976) was added at Ulvsundavägen as well as a parsonage and some service housing for tramway workers In 1914, tram line number 13 (Ulvsundabanan), a branch of the so-called Brommabanan, was pulled out to Ulvsunda via the pontoon bridge over Tranebergssund (later Traneberg Bridge).
At the same time, electricity was drawn to the area and a substation (Lillsjö station with associated residential buildings) was built at lövåsvägen according to designs by architect Gustaf de Frumerie.
In the 1920s and 1930s, expansion of private homes on plots with vacant lots continued, but in the 1940s the proportion of apartment buildings that later completely took over increased.
Street names related to Field Marshal Lennart Torstenson Some streets within Ulvsunda are named after Field Marshal Lennart Torstenson, who built Ulvsunda Castle and was the owner of the estate in 1644-1645, when the castle was built.
Some examples of roads in Ulvsunda district related to Torstenson and his estate are Fältmarskalkens Väg (1924), Forstenavägen (1924), Hamrabacken (1930) and Restadsvägen (1924).
ltmarskalkens väg/Fältmarskalksvägen was named after Field Marshal Lennart Torstenson, previously the road was called Lövåsvägen, named after a village under Ulvsunda, and first had been called Boställsvägen, after the new priest's residence, which was Bromma prästgård, Ulvsunda prästgård, and today is located on Lövåsvägen 12.
Forstenavägen was named after Forstena Manor in the Western Tunhems parish at the foot of Hunneberg in the present Vänersborg municipality in Västergötland, and there Lennart Torstenson was born 17 August 1603.
In the 1630s Lennart Torstenson owned two nearby farms in Stockholms-Näs parish at Görvälnsfjärden by Lake Mälaren in Uppland.
Hambra and Källvik were Crown Estates, which in 1573 was exchanged for frälsesäteri by Erik XIV's field Colonel Anders Rålamb.
These two farms, Hamra and Källvik, were merged in the 1690s by his son Anders Torstenson into an estate under the name Lennartsnäs and then belonged to his descendants until 1758.