Majha
The partition split the Punjab Province (British India) into the two states of West Punjab (Punjab, Pakistan) and East Punjab. However, the historic Majha region is arguably still the same as before since the partition does not change the previous history of Punjab, therefore does not change the geography of the Majha region of the historic Punjab region.
Punjabi Muslims
In 1947 the Punjab province of British India was divided along religious lines into West Punjab and East Punjab. Western Punjab was assimilated into the new country of Pakistan, while East Punjab became a part of modern-day India. This led to massive rioting as both sides committed atrocities against fleeing refugees.