Development regions of Nepal

Prior to the promulgation of a new constitution in 2015 after an earthquake, Nepal was divided into five development regions, 14 administrative zones and 75 districts. The 14 administrative zones were grouped into five development regions. Each district is headed by a Chief District Officer responsible for maintaining law and order and coordinating the work of field agencies of the various government ministries.
The five development regions of Nepal were :

No.	English name	Nepali name	Zones	Districts	Headquarters	Population	Area
1	Eastern Development Region	पुर्वाञ्चल विकास क्षेत्र	Mechi Koshi Sagarmatha	16	Dhankuta	5,811,555	28,456
2	Central Development Region	मध्यमाञ्चल विकास क्षेत्र	Janakpur Bagmati Narayani	19	Kathmandu	9,656,985	27,410
3	Western Development Region	पश्चिमाञ्चल विकास क्षेत्र	Gandaki Lumbini Dhaulagiri	16	Pokhara	4,926,765	29,398
4	Mid-Western Development Region	मध्य पश्चिमाञ्चल विकास क्षेत्र	Rapti Bheri Karnali	15	Birendranagar	3,546,682	42,378
5	Far-Western Development Region	सुदुर पश्चिमाञ्चल विकास क्षेत्र	Seti Mahakali	9	Dipayal	2,552,517	19,999.28

King Birendra divided the entire kingdom into four different regions in 2029 BS :

Eastern Development Region
Central Development Region,
Western Development Region
Far-Western Development Region

The three regions were:

Himalayan region, consisting of 21 districts
Hilly region, consisting of 35 districts
Terai region, consisting of 21 districts from east to west

To fill the gap between different parts of the nation by balanced or proportionate development. Eight years later, in 2037, he further divided the nation adding one more separate development region, naming it the mid-western development region, taking two zones from Far Western Development region Seti and Mahakali.