Quite right, PaulB, the Common Wealth means nothing, and the name is deceiving. It is a family occasion, really, I mean 'the family'!
The name Common Wealth had some meaning in the first half of the 16th century with the Church reform in England, but was never put into practice. The money and silver plates from the monasteries went to the king and his top allies, such as Thomas Cromwell, and the people who depended on monastery economy, including many sick and ill people, were tossed out on the street or laid redundant.
A common wealth would mean a common sharing of wealth, and not a family occasion, such as Henry VIII made it