Donald Currie & Company was founded in 1862 originally to operate between England and India, but soon after obtaining additional ships service was expanded to South Africa, around 1876 the name was changed to the Castle Mail Packet Company. In 1872 Robert Napier built the Windsor Castle for the line, a 334' long, 2,672 gross ton passenger/cargo ship, and it was this ship that secured the South African mail contract for Currie when she arrived at Table Bay on May 17, 1873 from Dartmouth in a record 23 days and 15 minuets, a full 50 hours faster than any previous ship.

The contract was not finalized until 1875 and Currie did not get exclusive rights, he would split the route with the Union Steamship Company. The two companies would provide mail service weekly, but since neither company on their own could accomplish this the companies would run alternately, a Union Steamship one week, a Castle Mail Packet the next. The contract stipulated that the passage should be made in 25 days and that for every day they were early a bonus of £100 would be paid to the line, of course for every day late the same would be paid by the company to the crown as a penalty.

The Windsor Castle sailed until the early morning hours of October 19, 1876 when she was nearing the end of a less than ideal voyage from Dartmouth. The weather was foul most of the way and a headwind had slowed the steamer considerably, so much that she was considered slightly overdue and there was some concern about the fate of the ship, she had been last spoken of Sept. 29 after leaving Maderia. As she neared her destination, Table Bay, she ran hard aground on the rocks off Dassen Island, the ship was stuck fast and her master, Capt. Hewatt, concluded that there was no chance of extracting the vessel.

The accident occurred at about 2 a.m. and the passengers, who were awakened by the sudden jolt, mostly went back to sleep believing that the ship had anchored. After about fifteen minuets the report came to the captain that the hull had been holed and that the engine room was flooded to the water line. The passengers were awakened and readied to abandon the ship. The weather was dead calm, but daylight was still a couple hours away so Hewatt waited until then to launch the boats. The evacuation was orderly and no panic was reported, all 244 passengers and crew got off the ship safely.

For the people now without shelter, but with a good stock of provisions, the wait for rescue was not a terrible ordeal as such circumstances have been for so many others. While they were inconvenienced, they were in no terrible danger of exposure or hunger. Two passengers, Lt. Melville of the 24th Regiment and a Mr. Searle from Port Elizabeth, volunteered to go overland to Cape Town and report the accident and arrange for help, they managed to obtain a couple of horses from some local farmers and arrived at Cape Town the next morning.

As soon as the accident was reported the agents for the company sent out the SS Florence to pick up the survivors and most of them boarded the ship and were taken to Cape Town. Some, however remained at the site of the wreck waiting for their luggage to be removed. All the luggage and the mails were removed and the remaining passengers and crew were later picked up and taken to Cape Town. The master was found to be at fault for being off course and his certificate was suspended for 9 months, the certificate of the 2nd Officer was suspended for 3 months.

For Donald Currie this was the first ship lost to his line, and it would be 1893 before another of his ships was wrecked. In 1900 the Castle Mail Packet Company merged with the Union Steamship Company and the Union-Castle Line was formed, this company survived under one name or another until the 1980's when it finally ceased operations.