Don’t splurge too much on mercenaries though, as getting into debt will set back the invasion. One around the 250 gold mark should be enough to cover it.

But, to increase your odds, you can hire a moderately priced mercenary unit. You will probably be able to win the war with the troops you already have. You will lose the host armies only when William dies (or if they are wiped out in battle), so you can use them even after the invasion is complete. Hit the Raise All Units button to raise all of Normandy's regular men-at-arms and vassal units. The units already raised on start are William's Hosts, special units that are free, do not cost any maintenance, and do not reinforce. It is difficult to ally the HRE however, as the Kaiser does not have any children at the start of the game. Denmark is a good option for your alliance and The Holy Roman Empire is the best option. The Desirable Match option under the glory tree is a good way to go, as it can help you get a better alliance through marriage. You will be able to select a Dynasty Legacy. Negotiate alliances with the Robert of Maine, Robert of Avranches and Odo of Bayeux, as indicated by the Notification Box. The +5 to battle advantage that this grants will be extremely useful for the coming battles. Select Chivalry focus in the Martial lifestyle tree, no matter which tree the game has rolled. At the very start of your game, ensure to complete the following tasks (some of which can be done before unpausing):

World conqueror 3 tips