The Kingstown (Dun Laoghaire) Mailboat was a lifeline between Dublin and the rest of the United Kingdom. As well as postal cargo, it carried civilians, much as car ferries do today. On the fateful morning of the 10th of October 1918, at 9 in the morning, the R.M.S. Leinster set sail as usual with a full crew; postal workers, civilian passengers and 300 British Army troops returning from home leave across the Irish Sea. 700 people were aboard in total.
Passengers were oblivious to the presence of a German U Boat, UB123, lying in wait nearby and ready to ambush. While the ship was passing 7 miles E.S.E. of Kish Light vessel, Robert Ramm, captain of the German submarine, ordered a torpedo to be fired at the Leinster. Having missed its target, another was fired. This one struck the Leinster and prompted her captain, William Birch, to turn back towards Kingstown. A third torpedo was launched from UB123, this time with catastrophic results. Within eight minutes the Leinster sank and 501 people lost their lives. This was the highest-ever loss of life in the Irish Sea.
Reaction to the sinking was swift. American president Woodrow Wilson, on hearing of the sinking, was furious:
“At the very time that the German government approaches the government of the United States with proposals of peace, its submarines are engaged in sinking passenger ships at sea”
UB123 was herself doomed to become a casualty of war; On the 18th of October 1918, while returning to Germany, she struck a mine in the North Sea. All hands were lost.
After the sinking of the Leinster, Reinhard Scheer, Admiral of the German High Seas Fleet, issued a communication stopping Germany’s policy of unrestricted submarine warfare which classed civilian passenger-carrying vessels as legitimate targets.
The communication read: “To all U-boats: Commence return from patrol at once. Because of ongoing negotiations any hostile actions against merchant vessels prohibited. Returning U- boats are allowed to attack warships only in daylight. End of message. Admiral”
One of the Leinster’s anchors was recovered and now lies at the side of Dun Laoghaire harbour near the Victoria monument, as a memorial to the dead. It was dedicated as a memorial on the 28th of January 1996.
The sinking of the Leinster resulted in the award of an Albert Medal for Bravery to Stoker William Maher, then a 33 year old father of eight. He dived repeatedly into the icy seas to rescue three people including 13-year-old Dorothy Toppin who many years later was to present an inscribed silver watch to William Maher in gratitude for saving her life.