What happened to Henry VIII on 28 January 1547 that almost killed him? Editorial note - 28 January 1547 is the date of Henry's death. If this is meant to be about the jousting accident, that occurred in January 1536.

A jousting accident.

King Henry VIII (aged 44) was unhorsed when competing in a jousting tournament at Greenwich Palace. The King was athletic and enjoyed many sports, though jousting was his favourite pastime.

The King was fully armoured, as was his charger which subsequently fell on him after he hit the ground. Reports vary, but Henry was knocked out or stunned, though not fatally wounded. Some felt that this accident caused changes to the King's personality.

https://www.historyskills.com/classroom/year-8/henry-viii-jousting-accident/