Procopius, vol. I (Palestine Pilgrims' Text Society), gives a full description of Constantinople.
The commentator, wrongly supposed to be Rashi, gives an interesting note upon the passage in I Chron. xx. 2, where it is mentioned that David took the crown of the king of the children of Ammon, and found it to weigh a talent of gold, and it was set upon David's head. Rashi states that the meaning of the passage must be that this crown was hung above David's throne, and adds that he heard in Narbonne that this practice was still kept up by the kings in the East.
See for a full account of these powerful Seljuk Sultans F. Lebrecht's Essay on the Caliphate of Bagdad during the latter half of the twelfth century. Vol. II of A. Asher's Itinerary of Rabbi Benjamin.
Ibn Verga, Shevet Jehuda, XXV, states that a predecessor of the Emperor Manuel Comnenus issued an edict prohibiting the Jews from residing elsewhere than in Pera, and restricting their occupation to tanning and shipbuilding.
This place is mentioned by Procopius, p. 119, as having been fortified by Justinian. It is now known as Rodosto.