In his speech following the declaration, he said the only reason the military was stepping in was to ensure democracy survives and vowed to hold free and fair elections in 90 days.

Zulfikar Ali Bhutto was prime minister at the time and relations with the military were sour. Some historians say Bhutto thwarted two military coups since being in office in 1971. Although he had come to an agreement with the opposition Pakistan National Alliance following the March elections, according to analysts, and they set to sign on July 5, General Zia declared martial law.

Although both PPP and NAP leaders were initially taken into custody and then released shortly after the imposition, Bhutto was later arrested on charges of murder. He was found guilty and executed in 1979.

General Zia did not deliver on elections in 90 days as promised. When they did take place, almost 90 months later, he had himself elected president in a referendum. He would hold two positions -- president and chief of army staff -- in the 11 years he ruled Pakistan.

Many took to Twitter to mark this day as a grim reminder of the struggles Pakistan has had to face on its path to democracy.

Someone found the opportunity to depict the impact of Zia's rule on Pakistan.