Complex sentence: In the beginning of July the area defended by Luck's "Kampfgruppe" came under the control of I SS Panzer Corps, commanded by Sepp Dietrich, and was reinforced with the Heavy Tank Battalion 503 equipped with Tiger I tanks.
Split into simpler sentences: In the beginning of July the area defended by Luck's "Kampfgruppe" came under the control of I SS Panzer Corps, commanded by Sepp Dietrich. Nearby was the Heavy Tank Battalion 503 equipped with Tiger I tanks.