743 Caspian Gates earthquake
The 743 Caspian Gates earthquake reportedly took place in the year 743 or 744 in the Caspian Gates (Gates of Alexander). The location is identified with either Derbent, Russia or Talis, Iran. 

The earthquake is recorded in sources from the Byzantine Empire. The chronicler Theophanes the Confessor (8th century) dates the earthquake in the year 6235 of the Byzantine calendar, in the third regnal year of Constantine V (reigned 741–775). This translates to year 743 or 744 of the Anno Domini system. According to Theophanes' narrative, a sign appeared in the north at the time of the earthquake, and dust fell in various places. This narrative is repeated by George Kedrenos (12th century), who used Theophanes as his source. 

According to a 1982 seismic catalogue by Ambraseys and Melville, this earthquake occurred to the east of Ray, Iran, in the valley of Tang-e Sar-e Darreh. Its recording in Byzantine sources would testify to this being a "large magnitude event". However the geographic term "Caspian Gates" was used for a number of mountain passes in the Caucasus. The passes linked the Mediterranean Sea regions to the Iranian Plateau and Central Asia. 

The term Caspian Gates was familiar to Greco-Roman authors. By the Byzantine era it mainly referred to the most important pass between the Caucasus and Northern Iran, the pass of Derbent. It was also known as "the Gate" or "the Gate of Gates". An Armenian translation of Pseudo-Callisthenes' "Alexander Romance" instead identifies the Caspian Gates with the territory of Talis. 

In the 19th century, Karl Ernst Adolf von Hoff and Robert Mallet theorized that the Caspian Gates should be identified with the pass of Dariel, which was located near the Black Sea. 
Q318277
Gates of Alexander
MISC
Q131416
Derbent
LOC
Q159
Russia
LOC
Q2427450
Talis
LOC
Q794
Iran
LOC
Q12544
Byzantine Empire
LOC
Q297584
Theophanes the Confessor
PER
Q1982627
Byzantine calendar
Concept
Q41635
Constantine V
PER
Q159791
Anno Domini
Concept
Q360883
George Kedrenos
PER
Q636188
Ray, Iran
LOC
Q39816
valley
Concept
Q133056
mountain pass
Concept
Q18869
Caucasus
LOC
Q4918
Mediterranean Sea
LOC
Q237660
Iranian Plateau
LOC
Q27275
Central Asia
LOC
Q5686841
Northern Iran
LOC
Q974482
Alexander Romance
Concept
Q73432
Karl Ernst Adolf von Hoff
PER
Q983172
Robert Mallet
PER
Q166
Black Sea
LOC
Q85738601
743 Caspian Gates earthquake
UNK
6235-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
6235
DATE
1982-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1982
DATE
+8^^http://www.w3.org/2001/XMLSchema#decimal
8
NUMBER
+775^^http://www.w3.org/2001/XMLSchema#decimal
775
NUMBER
+12^^http://www.w3.org/2001/XMLSchema#decimal
12
NUMBER
+19^^http://www.w3.org/2001/XMLSchema#decimal
19
NUMBER
country
country