City of Dublin Steam Packet Company

The City of Dublin Steam Packet Company was a shipping line established in 1823.

Up until 1850, the British Admiralty carried the Royal Mail, but in that year, contracts were awarded for the first time to private companies.

The most valuable route, with the highest volume, was between Kingstown (now Dún Laoghaire), in Ireland, and Holyhead in Wales.

These were twin-propeller vessels powered by an eight-cylinder steam engine, capable of 24 knots.

During World War I, the company lost two steamers sunk by the Germans, the worst of which was the second Leinster which was lost with over 500 lives in 30 metres of water just North East of the Kish Light, the greatest single-incident loss of life in the Irish Sea.