Bosworth 1465

Richard & the Yorks: Chris & Mark
Henry Tudor & the Lancastrians: Mike & Gary
Umpire & Stanley: Jim

Henry Tudor's army is marching onto the field from the far corner.
Norfolk's battle is deployed on the ridge.
Stanley's battle is in the right hand corner.
Richard's cavalry & Northumberland's battle is out of sight of Henry behind Norfolk.

Henry's army is deploying at the foot of the ridge.
Norfolk has advanced down the slope into bow range.
Richard's cavalry has appeared on Norfolk's right & Northumberland's battle on his left.

Henry's right has charged the Yorkist bowmen while his left forms up to face Richard's cavalry.

Henry's attack on Richard's left shuddered to a halt in the face a shower of hot dice from Chris.  Northumberland failed to obey Richards order to counterattack, but his bowmen sent Henry's billmen packing with a shower of 6's anyway. 

After a remarkable run of bad dice the Lancastrian infantry broke off their attack as Richard's cavalry pushed back Henry's on their flank.
Seeing the Lancastrians retiring, Stanley began an advance.  Richard prudently held back a cavalry unit to cover his flank, but the measure was rendered unnecessary by the general Lancastrian retreat.  All Stanley's doubts regarding Richard's claim to the throne evaporated the moment he saw Henry's cavalry break & he no intention of trying to pull Henry's arse out of the fire on his own.

With the Lancastrians in full retreat, Northumberland's battle also came to life & joined in the general pursuit.

The scenario had Richard's army significantly bigger than Henry's but had secret rules that Stanley & Northumberland would not do anything much until they could see who was going to win.  Thus Northumberland's battle halted on the crest & refused to move further while Norfolk & Richard slugged it out with Henry at the foot of the hill.  It should not have been as one-sided as it was, but in this battle the dice gods were firmly in the side of Richard.