The lighting of a unity candle is a relatively recent addition to the traditional wedding ceremony, most popular in the United States. The unity candle ceremony uses two taper candles with a large pillar candle (called the "unity candle '') in the center. At the beginning of the wedding ceremony, a representative from each family (usually the mothers of the bride and groom) light the two taper candles. Later in the ceremony (usually after the formal vows), the bride and groom use the two taper candles to light the large pillar (unity) candle together.
when do the bride and groom light the unity candle
usually after the formal vows