Ethiopian Orthodox priests perform the Dance of the Priests to celebrate Timkat (Epiphany), the church's most important Holy Day. Ethiopia is Africa's oldest Christian nation where more than half the population follows the Ethiopian Orthodox faith. During Timkat, priests stand in two rows, facing one another and sway gently as they chant. In addition to the staffs on their shoulders, they carry sistras, musical instruments, possibly of Egyptian origin, which have been used in religious ceremonies since Old Testament times. Attendants hold silk brocade umbrellas to shade them from the sun.