Complex sentence: In 1817, he was promoted to the rank of colonel and in 1819, at the age of 24, he was given the rank of brigadier general, making him one of the youngest Generals in the army.
Split into simpler sentences: In 1817, he was promoted to the rank of colonel. In 1819, at the age of 24, he was given the rank of brigadier general, making him one of the youngest Generals in the army.