The Bari Doab is the land between the Beas and the Ravi, named from Beas and Ravi as the Persian convention has it, taking the first syllables. It holds Lahore, Amritsar, Tarn Taran, Kasur, Gurdaspur and Batala.
It is the Majha, the heartland, the country that produced most of the Sikh misls, the Golden Temple, the Ghadar recruitment and a large part of the army recruitment.
The Upper Bari Doab Canal, taken from the Ravi at Madhopur from 1859, was the first major British irrigation work in Punjab and it made the district agriculture of Amritsar and Gurdaspur.
The 1947 line ran through the middle of it. Lahore and Amritsar, fifty kilometres apart, ended in different countries, and a doab that had been a single agricultural and social unit for two thousand years was cut in half.
The canal headworks stayed in India and the canal command area was mostly in Pakistan, which is the specific engineering fact that made the water dispute of 1948 and the treaty of 1960 necessary.
The country itself is flat, well watered and among the most fertile in the region, which is why it was fought over continuously and why every power that held the Punjab held Lahore first.
Kasur, Patti, Khem Karan and Bhikhiwind sit along the line now, and each of them was the market town for villages that are on the other side of it.
It is the most historically dense of the doabs. The Guru period sites, the Sikh state's core, the shrine of Baba Farid Ji at Pakpattan and both great cities are in it.