Before converting to Christianity through the missionary efforts of Robert Moffat, Afrikaner and his followers were considered notorious bandits.
Klaas and his sons would join farmer Petrus Pienaar on cattle rustling trips to the interior of the country.
He allowed Christian Missionaries to preach in his area, and followed them when they moved on eventually settling east of Warmbad.
This peaceful period ended in 1810, when Jager led an attack on the London Missionary Society at Pella following the illegal sale of some of the Orlam's cattle.
In February 1819, he travelled to the Cape Colony to petition Lord Charles Somerset to set aside the outlaw charge.