Lothal, before the arrival of Harappan people in about 2400 BCE, had been a small village next to the river providing access to the mainland from the Gulf of Khambhat.

The indigenous peoples maintained a prosperous economy, attested by the discovery of copper objects, beads, and semiprecious stones.

Ceramic wares were of fine clay and smooth, micaceous red surface.

They had improved a new technique of firing pottery under partly oxidizing and reducing conditions—designated black-and-red ware, to the micaceous Red Ware.

Harappans had been attracted to Lothal for its sheltered harbor, rich cotton and rice-growing environment and bead-making industry.

The beads and gems of Lothal are in great demand in the west.

The settlers live peacefully with the Red Ware people, who adopt their lifestyle—evidenced from the flourishing trade and changing working techniques—and Harappans began producing the indigenous ceramic goods, adopting the manner from the natives.

Harappans based around Lothal and from Sindh, after a flood destroys village foundations and settlements around 2350 BCE, take this opportunity to expand their settlement and create a planned township on the lines of greater cities in the Indus valley.

Lothal planners, to protect the area from consistent floods, divide the town into blocks of one-to-two-meter-high (three to six feet) platforms of sun-dried bricks, each serving twenty to thirty houses of thick mud and brick walls.

The city is divided into a lower town and a citadel, or acropolis, where the town’s rulers live.

The acropolis has paved baths, underground and surface drains built of kiln-fired bricks, and a potable water well.

The lower town is subdivided into two sectors—the north-south arterial street is the main commercial area—flanked by shops of rich and ordinary merchants and artisans.

The residential area is located to either side of the marketplace.

The lower town would also be periodically enlarged during Lothal's years of prosperity.

Lothal's dock—the world's earliest known—connects the city to a course of the Sabarmati river on the trade route between Harappan cities in Sindh and the peninsula of Saurashtra.

(The surrounding Kutch desert of today is at this time a part of the Arabian Sea.)

Engineers in Lothal accorded high priority to the creation of a dockyard and a warehouse to serve the purposes of naval trade.

While the consensus view among archaeologists identifies this structure as a "dockyard," it has also been suggested that owing to small dimensions, this basin may have been an irrigation tank and canal.

The dock was built on the eastern flank of the town, and is regarded by archaeologists as an engineering feat of the highest order.

It was located away from the main current of the river to avoid silting, but provided access to ships in high tide as well.

The warehouse was built close to the acropolis on a 3.5 meter-high (10.5 ft) podium of mud bricks.

The rulers could thus supervise the activity on the dock and warehouse simultaneously.

A mud-brick wharf, two hundred and twenty meters (seven hundred and twenty feet) long, built on the western arm of the dock, with a ramp leading to the warehouse, facilitates the movement of cargo.

The superstructure of an important public building opposite to the warehouse has completely disappeared.

Throughout their time, the city had to brace itself through multiple floods and storms.

Dock and city peripheral walls were maintained efficiently.

The town's zealous rebuilding ensured the growth and prosperity of the trade.

However, with rising prosperity, Lothal's people failed to upkeep their walls and dock facilities, possibly because of overconfidence in their systems.

A flood of moderate intensity in 2050 BCE exposed some serious weaknesses in the structure, but the problems were not addressed properly.

The uniform organization of the town and its institutions give evidence that the Harappans were a highly disciplined people.

Commerce and administrative duties were performed according to standards laid out.

Municipal administration was strict—the width of most streets remained the same over a long time, and no encroached structures were built.

Householders possessed a sump, or collection chamber to deposit solid waste in order to prevent the clogging of city drains.

Drains, manholes, and cesspools kept the city clean and deposited the waste in the river, which was washed out during high tide.

A new provincial style of Harappan art and painting was pioneered.

The new approaches included realistic portrayals of animals in their natural surroundings.

Metalware, gold and jewelry and tastefully decorated ornaments attest to the culture and prosperity of the people of Lothal.

Most of their equipment: metal tools, weights, measures, seals, earthenware and ornaments were of the uniform standard and quality found across the Indus civilization.

Lothal was a major trade center, importing en masse raw materials like copper, chert, and semiprecious stones from Mohenjo-daro and Harappa, and mass distributing to inner villages and towns.

It also produced large quantities of bronze celts, fishhooks, chisels, spears, and ornaments.

Lothal exported its beads, gemstones, ivory, and shells.

The stone blade industry catered to domestic needs— fine chert was imported from the Sukkur valley or from Bijapur in modern Karnataka.

Bhagatrav supplied semiprecious stones while chank shell came from Dholavira and Bet Dwarka.

An intensive trade network, which stretches across the frontiers to Egypt, Bahrain, and Sumer, gives the inhabitants great prosperity.

One evidence of trade in Lothal is the discovery of typical Persian Gulf seals, a circular button seal.

The wider debate over the end of Indus civilization continues, but evidence gathered by the archaeological Survey of India appears to point to natural catastrophes, specifically floods and storms as the source of Lothal's downfall.

A powerful flood submerged the town and destroyed most of the houses, with the walls and platforms heavily damaged.

The acropolis and was leveled (2000-1900 BCE), and inhabited by common tradesmen and newly built makeshift houses.

The worst consequence was the shift in the course of the river, cutting off access to the ships and dock.

The people built a new but shallow inlet to connect the flow channel to the dock for sluicing small ships into the basin.

Large ships were moored away.

Houses were rebuilt, yet without removal of flood debris, which made them poor-quality and susceptible to further damage.

Public drains were replaced by soakage jars.

The citizens did not undertake encroachments, and rebuilt public baths.

However, with a poorly organized government, and no outside agency or central government, the public works could not be properly repaired or maintained.

The heavily damaged warehouse was never repaired properly, and stocks were stored in wooden canopies, exposed to floods and fire.

The economy of the city was transformed.

Trade volumes reduced greatly, though not catastrophically, and resources were available in lesser quantities.

Independent businesses caved, allowing a merchant-centric system of factories to develop where hundreds of artisans worked for the same supplier and financier.

The bead factory had ten living rooms and a large workplace courtyard.

The coppersmith's workshop had five furnaces and paved sinks to enable multiple artisans to work.

The declining prosperity of the town, paucity of resources and poor administration increase the woes of a people pressured by consistent floods and storms.

Increased salinity of soil makes the land inhospitable to life, including crops.

This is evidenced in adjacent cities of Rangpur, Rojdi, Rupar and Harappa in Punjab, Mohenjo-daro and Chanhudaro in Sindh.

A massive flood in about 1900 BCE destroys the flagging township in a single stroke.

Archaeological analysis shows that the basin and dock were sealed with silt and debris, and the buildings razed to the ground.

The flood affects the entire region of Saurashtra, Sindh, and south Gujarat, and affects the upper reaches of the Indus and Sutlej, where scores of villages and townships are washed away.

The population flees to inner regions.

Archaeological evidence shows that the site continued to be inhabited, albeit by a much smaller population devoid of urban influences.

The few people who returned to Lothal could not reconstruct and repair their city, but surprisingly continued to stay and preserved religious traditions, living in poorly built houses and reed huts.

That they were the Harappan peoples is evidenced by the analyses of their remains in the cemetery.

While the trade and resources of the city were almost entirely gone, the people retained several Harappan ways in writing, pottery, and utensils.

ASI archaeologists record a mass movement of refugees from Punjab and Sindh into Saurashtra and to the valley of Sarasvati about this time (1900-1700 BCE).

Hundreds of ill-equipped settlements have been attributed to this people as Late Harappans a completely de-urbanized culture characterized by rising illiteracy, less complex economy, unsophisticated administration and poverty.

Though Indus seals go out of use, the system of weights, with an 8.573-gram (0.3024 oz. avoirdupois) unit, is retained.

Trade revives in the Indus Valley between 1700 BCE and 1600 BCE.

In Lothal, Harappan ceramic works of bowls, dishes and jars are mass-produced.

Merchants use local materials such as chalcedony instead of chert for stone blades.

Truncated sandstone weights replace hexahedron chert weights.

The sophisticated painting style reduces itself to wavy lines, loops and fronds.

The postulated Indo-European invaders of the Indus Valley, if such an event actually occurs, apparently absorb a small fraction of the older population, probably female consorts and enslaved artisans, and eventually appropriate significant aspects of the older culture.