Marriage of his Son Constantius Cæsar
On the completion of the thirtieth year of his reign he solemnized the marriage of his second son, having concluded that of his first-born long before. This was an occasion of great joy and festivity, the emperor himself attending on his son at the ceremony, and entertaining the guests of both sexes, the men and women in distinct and separate companies, with sumptuous hospitality. Rich presents likewise were liberally distributed among the cities and people.
Source: Life of Constantine (New Advent)