The area that now consists of Karachi was originally a group of small villages including Kalachi-jo-Kun and the fort of Manora. Any history of Karachi prior to the 19th century is sketchy. It is said that the city called Krokola from which one of Alexander the Great's admirals sailed at the end of his conquests was the same as Karachi. When Muhammad bin Qasim came to India in the year 712 he captured the city of Debul. It has been said that Debal was the ancestral village of present day Karachi. However, this has neither been proven or disproven.

It was in 1729 that Kolachi-jo-Goth was transformed from a fishing village to a trading post when it was selected as a port for trade with Muscat and Bahrain. In the following years a fort was built and cannons brought in from Muscat were mounted on it. The fort had two doorways, one facing the sea called the Khara Darwaza or Brackish Gate and one facing the River Lyari called the Meetha Darwaza or Sweet Gate. In 1795 the city passed from the Khan of Kalat to the Talpur rulers of Sindh.

Karachi gained in position as a major port and rapidly developed as an important city. The importance of the Indus and Sindh led the British to capture the city on the 3rd of February 1839 starting an era of foreign rule and colonial subjugation that was to end in 1947. A famous quote about Karachi attributed to Charles Napier is "Would that I could come again to see you in your grandeur!". Napier's quote proved almost prophetic as it was under the British raj that Karachi would grow as its harbour was developed. On the 10th of September 1857 the 21st Native Infantry stationed in Karachi declared allegiance to the Emperor Bahadur Shah Zafar and joined the cause of the War of Independence of 1857. The uprising was defeated by the British who reasserted their control within a matter of days.

In 1876, the founder of Pakistan Muhammed Ali Jinnah was born in the city, and he would later be buried there. By this time Karachi was a city with railroads, churches, paved streets, courts and many commercial centres as well as a magnificent harbour built by the British. Many of the buildings were built in classical British colonial style, contrasting significantly with the "Mughal Gothic" of Lahore. Many of these old buildings exist today and provide interesting destinations for visitors.

Karachi continued to grow in size as well as importance due to its position as a major port. A railroad connected Karachi to the rest of British India in the 1880s. In 1899 Karachi was said to be the largest wheat exporting port in the East (Feldman 1970:57). In 1911 when the capital was shifted to Delhi, Karachi became closer to being a Gateway to India. Karachi was declared the capital of the newly formed Sindh province in 1936, chosen over the traditional capital of Hyderabad.

In 1947, Karachi was made the capital of the new nation of Pakistan. At that time Karachi was a city of only 400,000 people, and its growth accelerated as a result of its new status. Being the capital, Karachi became a focal point for the new nation and this added to its status as a cultural centre in this part of the world. Although the capital later moved to Rawalpindi and then Islamabad, Karachi remains the economic centre of Pakistan, accounting for a large portion of the GNP of the nation and a large chunk of the nations white collar workers.

In the last 20 years, Karachi has continued to grow, passing the ten million mark. It is a city of diverse neighbourhoods, ranging from the upscale Clifton and Defence areas to numerous slums that are home to the large numbers of migrants who have flocked to Karachi in search of opportunities.

The current economic boom in Pakistan has created a sudden growth spurt in Karachi as jobs and infrastructure projects are increasing with time.