Symbolism and imagery in religious art Crossword

Used commonly since the 4th century as a symbol of Jesus' death (5)
A cross with the figure of Jesus, used since the 5th century (8)
Another word for the fish symbol (7)
The fish was used as a secret symbol when Catholics were under ............ (11)
Ichthus is an ......... for "Jesus Christ, Son of God, Saviour" (8)
A symbol made from the first two letters of the Greek word for Christ:XP (3,3)
The Chi Rho was on this emperor's shield in the battle against Maxentius (11)
A symbol of the Holy Spirit and Baptism (4)
A sign of Jesus' divine nature, those who wait patiently for God will be rewarded with wings of this (5)
The first letter of the Greek alphabet, representing eternity of Christ (5)
The last letter of the Greek alphabet, representing eternity of Christ (5)
Four gospel writers (11)
Special separate buildings containing the baptismal pool, popular in Italy (12)