Christ’s Ascension into Heaven is commemorated on a Thursday forty days after Easter. Tradition places the event on the Mount of Olives, to the east of Jerusalem. It was the culmination of a period of post-resurrection appearances in which Jesus is said to have visited with his disciples. Christians have been observing the day since at least the end of the fourth century. Now, on the site traditionally connected with the event stands not a church but a small mosque. Ten days after the Ascension, the feast of Pentecost (“Fifty”) recalls how Jesus promised his disciples he would soon send a “paraclete,” or advocate, to continue guiding the young community in his stead. Tradition identifies the paraclete as the Holy Spirit. The Acts of the Apostles recounts how the disciples were gathered in an upper room when something like a storm enveloped them, and they experienced the power of the Spirit descending upon them in “tongues as of fire.” Many Christians refer to this event as the birthday of the Church, since it gave the disciples the courage to emerge from hiding to preach the Gospel far and wide.