Gavrilo was a soldier in the Kaedwenian Army prior to the Third Northern War, as well as former member of the Salamandra gang.
Upon meeting Gavrilo in the Kaedweni camp during Chapter II, Geralt will recognize him, leading to Gavrilo's confession about having worked for Salamandra and being spared by Geralt. Gavrilo hopes Geralt to bear no grudge and will offer a "trinket" (Robust Well-Balanced Silver Dagger) as compensation.