23rd March 1940 Pakistan resolution was passed in Lahore. At that time is was known by Lahore Resolution (Qardade-e-Lahore). If there is a single most important founding document of Pakistan, it has to be this Resolution passed at the annual session of the All India Muslim League at its 1940 meeting (22-24 March) at Minto Park (now called Iqbal Park), Lahore (by the way, what a wonderful idea – for political parties to have annual, open, meaningful, annual sessions where real decisions are taken in a transparent and democratic manner!). In 1941, this Lahore (Pakistan) Resolution became part of the Muslim League constitution and in 1946 it became the basis of the demand for Pakistan.
Here is some latest collection of High Resolution wallpapers of 23rd March