Siward  

(Pronounced sea-ward)

Siward is spelt si-ward and to remember this use the following mnemonic:

Siward was in a very sick ward of the hospital.

Siward (pronounced sea-ward) is the Earl of Northumberland and leader of the English army that is used to defeat Macbeth.

To remember these facts use the following mnemonic:

Siward decides to get out of the sick bed and look seaward. Looking out he could see the North Pole under an umbrella on land (Northumberland). Behind that stood the English army.