We have had a thread on Roman coins with long legends: https://www.cointalk.com/threads/roman-coin-with-the-longest-legend.330700/ It includes some Roman provincial coins. We don't expect Greek coins to have long legends. But, coins with Arabic legends might have long legends; most Arabic coins have only legends! However, not many of us collect coins with legends we can't read. The exception is perhaps "Turkoman figural bronzes" from the period around AD 1200 which do have figures. Sometimes the Turkoman peoples are called "Foes of the Crusaders." They are easy to collect because there are several books about them. Most commonly cited are volumes 1 and 2 of "Turkoman Figural Bronze Coins and Their Iconography" by Spengler and Sayles. Unfortunately, it is not complete because Spengler took ill and died before volume 3 could be written. Wilkes completes the list, however without the explanation, translation, or commentary, in "Islamic Coins and Their Values." Here is one with a very long legend. 28 mm. 15.81 grams. Qubt al-Din Muhammad b. Zengi, AH 594-616, AD 1197-1219. Struck at Singar, AH 600 = 1203, a year when the crusaders of the Fourth Crusade reached and besieged Constantinople. S/S 82. Wilkes 1276. Sayles thought the bust is that of Athena, of the famous statue formerly in the temple at Athens, that was pulled down that year by superstitious citizens of Constantinople. He has pages of discussion. You can see it has a lot of letters. It mentions his name, his overlord Calif al-Nasir, and the Sultan's name, 'Adil Saif al-Din Abu Bakr. I don't know how to count Arabic letters, but I can count the letters in the English transliteration given by Spengler. On the obverse there are 70 and on the reverse 77 in the middle, 8 to the left, 19 to the right, and 4 above. So, in total there are 178 letters. Beat that!
Dunno if I can beat that, but Suleiman is yakkin’ alot! SULEIMAN the MAGNIFICENT: Ottoman Empire Suleiman the Magnificent 1520-1566 CE AV Sultani Constantinople mint 1520 CE 19mm 3.5g
The reverse isn't good on this piece, but this dirham of the Saffarid dynasty of Persia has... a lot of letters on both obverse and reverse. (Obverse has _two_ full circles of text in the margins, while the reverse has just one circle of text.) Saffarids, Tahir b.Muhammad, AH 289. No more info posted at this time because I haven't done a full write-up of this piece yet.
Well, this one is a little unfair since it was struck for three co-rulers and a caliph – but I'm pretty sure it's the longest legend I have in my collection. I count about 190 characters: Seljuq Sultanate of Rum, under Kayka'us II, Qilij Arslan IV, Kayqubad II ("the three brothers"), citing caliph al-Musta'sim, AR dirham, 1249–1250 AD (647 AH), Siwas mint. Obv: kalima and citation of caliph "la ilah illa allah / muhammad rasul allah al-imam / al-musta'sim billah amir al-mu / 'minin;" afterwards mint and date formula for Siwas 647 AH. Rev: names and titles of the three brothers: "al-salatin al-a'azim / 'izz al-dunya wa ud-din kay kawus / wa rukn al-dunya wa ud-din qilij arslan / wa ’ala al-dunya wa ud-din kayqubad / ibn kay khusraw barahin amir al-mu’minin." 23mm, 3,02g. Ref: Album 1227. The coin also has some pretty impressive and colorful titles. The reverse translates into: “The rulers and supreme ones: the glory of the world and the faith Kayka’us, and the pillar of the world and of the faith Qilij Arslan, and the exalted of the world and the faith Kayqubad ibn Kaykhusraw, supporters of the commander of the faithful.”
