For most of the eighteenth, nineteenth and part of the twentieth century, visitors to the Umayyad Mosque's western portico saw plain plastered walls, not mosaics. At some point during the long Ottoman period of control over Damascus, from 1517 to 1922, the original Umayyad mosaic decoration was covered over, for reasons no surviving record fully explains; plaster was simply cheaper to maintain than delicate glass tesserae, and later generations may not have known, or cared, what lay underneath.
The covering held until 1893, when a serious fire swept through the mosque. The heat cracked sections of the plaster, and workers repairing the damage noticed glass tesserae glinting through the breaks, the first clue in a century or more that the mosaics had survived at all rather than having been destroyed or removed. It took more than three decades for a systematic response: from 1928, Victor Eustache de Lorey, director of the French Institute in Damascus during the French Mandate period, led a careful restoration campaign specifically aimed at removing the covering plaster and stabilising whatever mosaic remained beneath it.
The result exceeded expectations. Rather than fragments, de Lorey's team uncovered a largely intact 34.5 metre panel, unveiled to the public in 1929 in the same western portico it had always occupied. Nearly four centuries of concealment had, if anything, protected the mosaic from further wear, and the Barada Panel returned to view essentially as Umayyad craftsmen had left it in the early eighth century, one of the most complete surviving examples of early Islamic monumental mosaic art anywhere.