 Complete the following phrase:  People have used this route since antiquity - both Strabo in his Geographica and Pliny the Elder mention it. Russian troops first travelled it in 1769. Pavel Potemkin sent 800 troops to improve the road so that by October 1783 he was able to drive to Tiflis in a carriage drawn by eight horses. The Georgian Military Road in its present form was begun by the Russian military in 1799, after the Georgians had abjured centuries of Persian suzerainty and became a Russian protectorate under the 1783 Treaty of Georgievsk. Russian control of the Georgian Military Highway in the center of the Caucasus divided the 