The William IV Cup is named after the monarch who formally defined the close relationship between the HAC and its sister Regiment - The Grenadier Guards. The link between the two units goes back the Grenadiers foundation in Bruges when Charles II was in exile. A number of HAC Officers helped establish the Grenadiers. The match is a challenge match - hosted by the HAC - where the two regimental teams compete for the William IV Cup. The day also sees a HAC and Grenadier veterans team play each other.