Eusebius and other writers report an earthquake that caused destruction in Sidon and Tyre, with strong shaking felt in Caesarea. The exact date of the event is uncertain because the sources contradict one another regarding the year. Proposed dates fall between 300 and 306 CE, with 303–306 CE generally considered the most likely interval and either 303 or 306 CE the most probable year.

In his work Martyrs of Palestine, Eusebius provides a specific month and day—April 2—and appears to imply a year around 306 CE. Ambraseys (2009) instead assigned the earthquake a precise date of 2 April 303 CE by combining the day and month reported in Martyrs of Palestine (a contemporaneous source) with an interpretation of History Against the Pagans by Orosius. Although Orosius does not provide an explicit year, his narrative may imply that the earthquake occurred near the beginning of the Diocletianic Persecution in 303 CE.

Some earthquake catalogues claim that this event generated a tsunami at Caesarea. While this remains possible, no tsunamogenic evidence has yet been identified. The report ultimately derives from Eusebius, but the wording of the passage is ambiguous and does not clearly distinguish between a tsunami, unusually strong waves, or a storm surge. It is therefore possible that the description reflects rhetorical embellishment or hyperbolic narrative rather than a literal observation.

Archaeoseismic evidence for this earthquake is limited, but paleoseismic evidence is somewhat stronger. Wechsler et al. (2014) associated Event CH4-E3 at Bet Zeyda—just north of the Sea of Galilee—with the Eusebius Martyr earthquake. The modeled age range for this event is 250–310 CE, which overlaps the historical timeframe. Sbeinati et al. (2010) also reported a seismic event (Event X) dated to 335 CE ± 175 years at a displaced Roman aqueduct near al-Harif, Syria, close to Masyaf. Although the dating range is broad, the event could potentially correspond to the earthquake described by Eusebius. Event X is associated with strike-slip movement on the Missyaf fault segment (also known as the Ghab Fault), whose southern end lies approximately 142 km from Sidon. This distance is somewhat large for explaining the reported damage.

However, if rupture also propagated onto the Yammouneh fault segment, the geometry changes significantly. The southern end of the Yammouneh fault lies only about 35 km from Sidon and Tyre. A rupture extending onto this segment could therefore explain the reported destruction in those cities and would imply a very large earthquake. Such a rupture near the southern end of the Yammouneh fault could also account for the paleoseismic evidence at Bet Zeyda and would suggest that structures in the Galilee region may have suffered damage as well.