Family Torroja was the lineage that between the 11th and 13th centuries ruled the town of Solsona (which currently has more than 400 years holding the title of city). The Torroja were descendants of the Earl looked at, Lord of Solsona is now who in the year 990 documented. Arnau was one of four grandchildren. As for his father, Ecard-Miro, was who built the so-called castle today called Castell Vell (old Castle, because he was on the mountain called long before old, as an Iberian settlement) at the top of the hill near Solsona. The Castle whose silhouette to lose its outer wall, today it seems to be a natural pyramid dominating Solsona, to be finished its campus, had a square ground plan and a circular tower at each angle. From there a very vast territory is dominated visually to your around. The old Solsona was then under the level where they built the Romanesque church. This and the residence of the Lord of Solsona, although today presented one at each end of the city, then remained fairly away between Yes, and walk represented a good way across what had to be the gardens of the fortified Palace, which was the family residence of the noble Lord.
It is ignored when was exactly born Arnau de Torroja, but if we consider that it was shortly after 1122, the error has to be minimum. His parents had married in 1104, shortly after fathering the child heir Ramon I (died February 1, 1144), who succeeded by his son Ramon II, nephew of Arnau, and involved as he and his brother ecclesiastical in large companies of the reconquest from Almeria to the main Muslim towns in Catalonia. Arnau de Torroja was born when Alfonso I de Aragon coveted to snatch the Muslims the city of Zaragoza, aided by the count of Toulouse from the Languedoc. .