On 20 March 1731 the Gargano peninsula was struck by one of the strongest earthquakes (IX MCS), with the epicentre located near Foggia, some 30 km from the coast. Tsunami effects were observed at Siponto and Barletta, where sudden sea rise nearly shipwrecked some boats. In a contemporary document (Cirillo, 1731) and a historic earthquake catalog (Mallet, 1853) this tsunami event was dated as 9 March, but later studies have related it to the major eartquake of 20 March. I = 4, R = 4.