The national flag of Bangladesh  (Bengali: বাংলাদেশের জাতীয় পতাকা) was adopted officially on 17 January 1972. It is based on a similar flag used during the Bangladesh Liberation War of 1971. The map was later deleted from the flag by the order of General Abul Manzur, most likely to simplify the design[citation needed]. A red disc is on top of the green field, offset slightly toward the hoist so that it appears centred when the flag is flying. The red disc represents the sun rising over Bengal, and also the blood of those who died for the independence of Bangladesh. The green field stands for the lushness of the land of Bangladesh. The red disc is a socialist symbol of the rising Sun of independence after the dark night of a blood-drenched struggle against Pakistan.

Origin
The original flag was designed by painter Quamrul Hassan. On 2 March 1971, the initial version of the flag was hoisted in Bangladesh for the first time at the Dhaka University. As the Vice President of Dhaka University Students’ Union (DUCSU), student leader A. S. M. Abdur Rab hoisted the flag. On the declaration of Independence on 26 March 1971, Sheikh Mujibur Rahman flew the flag in his residence.

The flag was conceived so as to exclude the crescent and the star considered as symbols of West Pakistan. According to Flags of the World, the green used in the flag does not represent the traditional colours of Islam, contrary to some western sources (such as the CIA World Fact Book). Rather, the green colour was chosen to represent the lushness of the natural landscape of Bangladesh. The current flag resembles the flag of Japan with the background a different colour.

The map was removed from the flag in 1972. One reason given was the difficulty rendering the map correctly on both sides of the flag.

The Bangladesh flag as it is today:

In the World Flag this flag has important design balance and appears center right of the earth image. See World Flag Symbolism  and History post.

Source: Wikipedia