I reproduce below one of several internet bios of Ventura, who arrived in Ranjit Singh`s court in Lahore in 1822 and was almost immediately given a post as a general and `reorganized the infantry` among other things,
Reading the data, we find that V was only 11 years old when N was exiled to St Helena and can have been only 28 when he arrived in Lahore. He was obviously a prodigy.
There are other entries to be found; all give his dob as 1794. He was obviously raised on Weetabix.

`Jean-Baptiste (Giovanni Battista) Ventura, born Rubino ben Torah (25 May 1794 – 3 April 1858), was an Italian soldier, mercenary in India and early archaeologist of the Punjab region of the Sikh Empire.

`Ventura was born in Finale Emilia in the Duchy of Modena to Jewish parents and received a conventional Jewish education. At the age of seventeen Ventura enrolled as a volunteer in the militia of the Kingdom of Italy and later served with Napoleon's imperial army where he reached the rank of colonel of infantry. After the Waterloo and the final downfall of Napoleon he returned to his home; but in 1817,