The passenger steamship SS Princess Alice sank in the River Thames after colliding (pictured) with the collier Bywell Castle, killing more than 600 people.

SS Princess Alice, formerly PS Bute, was a British passenger paddle steamer that sank on 3 September 1878 after a collision with the collier SS Bywell Castle on the River Thames. Between 600 and 700 people died, all from Princess Alice, the greatest loss of life of any British inland waterway shipping accident. No passenger list or headcount was made, so the exact figure of deaths has never been known.

The River Thames, known alternatively in parts as the River Isis, is a river that flows through southern England including London. At 215 miles (346 km), it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn.

A collier is a bulk cargo ship designed or used to carry coal. Early evidence of coal being transported by sea includes use of coal in London in 1306. In the fourteenth and fifteenth centuries, coal was shipped from the River Tyne to London and other destinations. Other ports also exported coal – for instance the Old Quay in Whitehaven harbour was built in 1634 for the loading of coal. London became highly reliant on the delivery of coal by sea – Samuel Pepys expressed concern in the winter of 1666–67 that war with the Dutch would prevent a fleet of 200 colliers getting through. In 1795, 4,395 cargoes of coal were delivered to London. By 1824, this number had risen to about 7,000; by 1839, it was over 9,000. The trade continued to the end of the twentieth century, with the last cargo of coal leaving the Port of Tyne in February, 2021.

Bywell Castle was a passenger and cargo ship that was built in 1869 by Palmers Shipbuilding and Iron Company, Jarrow, County Durham. She was involved in the Princess Alice Disaster in September 1878 in which more than 600 people died. She disappeared in February 1883 whilst on a voyage from Alexandria, Egypt to Hull, Yorkshire, United Kingdom.