LONDON (AP) — Royal wedding organizers are preparing for a rehearsal of the proceedings to take place in Windsor — but without the bridge and groom.

Planners will use Thursday's practice session to finalize some of the details of Saturday's gala wedding at St. George's Chapel on the grounds of Windsor Castle.

The festivities will include a 25-minute carriage ride outside the castle grounds by the newlyweds Prince Harry and Meghan Markle after the ceremony is concluded.

A large military contingent will also take part, reflecting Harry's years of military service.

It is not clear who will walk Markle down the aisle. Her father Thomas Markle had been selected for that role but is reportedly ill with heart problems.

Markle's mother Doria Ragland may take Thomas Markle's place if needed.