Srimad Bhagavatam Canto 03, Chapter 01, Text 20

SB 3.1.20

ittham vrajan bharatam eva varsam
kalena yavad gatavan prabhasam
tavac chasasa ksitim eka cakram
ekatapatram ajitena parthah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Thus, when he was in the land of Bharatavarsa traveling to all the places of pilgrimage, he visited Prabhasaksetra. At that time Maharaja Yudhisthira was the emperor and held the world under one military strength and one flag.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
More than five thousand years ago, while Saint Vidura was traveling the earth as a pilgrim, India was known as Bharatavarsa, as it is known even today. The history of the world cannot give any systematic account for more than three thousand years into the past, but before that the whole world was under the flag and military strength of Maharaja Yudhisthira, who was the emperor of the world. At present there are hundreds and thousands of flags flapping in the United Nations, but during the time of Vidura there was, by the grace of Ajita, Lord Krsna, only one flag. The nations of the world are very eager to again have one state under one flag, but for this they must seek the favor of Lord Krsna, who alone can help us become one worldwide nation.
Srimad Bhagavatam Canto 03, Chapter 01, Text 19
Srimad Bhagavatam Canto 03, Chapter 01, Text 21