The American is bidding over the next three weeks and 3,500 km to surpass fellow five-times winners, Jacques Anquetil, Bernard Hinault, Eddy Merckx and Miguel Indurain.
Even though Armstrong, German Jan Ullrich and American Tyler Hamilton could feature prominently in the 6.6-km Tour opener, specialists like Australia's Bradley McGee are expected to steal the show on the first day of the race.
Liege is hosting the Tour for the 10th time and the race will stay in Belgium for three days before returning to France on Tuesday.
