George Penelis is emeritus professor of concrete and masonry structures at Aristotle University of Thessaloniki, Greece. He has led the design or the review of many prominent reinforced concrete buildings and the structural restoration or review of some of the best-known monuments in the Mediterranean Basin, including the Rotunda in Thessaloniki, the National Library in Athens, the rotunda of Saint George in Cairo, and the Hagia Irene of Istanbul. He is co-author of Earthquake-Resistant Concrete Structures; and (with Gregory Penelis) of Concrete Buildings in Seismic Regions 2nd ed - both published by Taylor & Francis. Gregory Penelis is CEO and consulting structural engineer with a PhD from the Aristotle University of Thessaloniki. He has been involved in many research projects regarding the seismic risk assessment of masonry buildings, monuments and urban nucleus. He was awarded the 2016 Structural Award and 2016 ENR Global Best Project Award for the Stavros Niarchos Cultural Center in Athens and the 2017 ENR Global Best Project Award for the Restoration of the Margirgis Church and Roman Tower in Cairo He has also developed software for the seismic design of R/C and masonry buildings. He has been honoured twice with the gold medal of the order of Leon by the Patriarch of Alexandria and All Africa Theodoros II.