As Archbishop Adolf, the protagonist of the war, took his position, various forces surrounding Mainz began to act.
The Archbishop of Trier and the Count of Nassau invaded Mainz and northern Palatinate from two directions respectively, and their progress was quite smooth.
To the south, the Margrave of Baden's invasion met no resistance, and soon, Palatinate's scattered territories on the left bank of the Rhine River successively fell.
Meanwhile, the Imperial Army, the Württemberg Army, and the Speyer Army, led by Adolf, slowly advanced into Palatinate territory on the right bank of the Rhine River.
Throughout the spring of 1462, the allied forces did not attempt any large-scale offensive against the Mainz-Palatinate alliance.
On one hand, it was because the allied forces were not well-informed about the movements of the Elector Palatine and his army, fearing that a rash advance would lead to an ambush. On the other hand, the allied forces were still gathering their troops, needing to concentrate all their strength to decisively defeat the resistance of Palatinate and Mainz.
In the early stages of the war, both sides continued to probe, with the allied forces gradually encroaching upon Palatinate territory. The Margrave of Baden was the most active among them, and he was also the one who gained the most actual territory during this phase.
Adolf even reasonably suspected that the Margrave of Baden had intentionally provoked the war with Palatinate to firmly bind them to their war chariot.
He had been quite moved at first, but it turned out the Margrave of Baden couldn't hide his petty intentions at all.
As soon as the war began, his greed was fully exposed. The Margrave seemed as if he had never seen land before, continuously attacking, plundering, and occupying Palatinate's territories. Time flew, and it was soon early summer of 1462.
Under Adolf's repeated urging, the Margrave of Baden reluctantly abandoned the sparsely defended Palatinate Rhine River territories and led his army to the Bretten fortress in the Bishopric of Speyer to rendezvous with the allied forces.
The total strength of the allied forces finally exceeded ten thousand, reaching the anticipated twelve thousand troops.
Of course, most of these were temporarily conscripted serf soldiers. The only truly capable fighters were the knight lords and the commanders' bodyguards, as well as the standing mercenaries provided by the Emperor.
When they first saw this well-equipped and well-trained army, everyone was amazed.
Especially upon seeing the fast-moving war chariots and cannons, as well as the peculiar new matchlock guns, the Count of Württemberg and the Margrave of Baden made no secret of their envy, longing, and deep reverence.
Thinking that the Emperor had tens of thousands more such troops, they began to laugh at the foolishness and overestimation of the Elector Palatine and the Mainz rebels.
The hot, humid air of summer made the people in the council hall of Bretten Castle somewhat agitated.
"Gentlemen, according to reliable intelligence from our spies, the Elector Palatine is still in Bavaria, seemingly preparing to join forces with the Duke of Landshut to attack the Margrave of Ansbach," Adolf stared intently at the map on the table, a flicker of irrepressible fanaticism in his eyes. "Currently, the Palatinate homeland is thinly defended and vulnerable.
This is undoubtedly a heaven-sent opportunity for us to advance on Mainz and thoroughly defeat Dieter and his faction!"
The Count of Württemberg frowned deeply, keenly sensing that something was amiss. He asked in a deep voice, "This intelligence seems incorrect, doesn't it? The Elector Palatine has been allied with Dieter for a long time. Now that the war has been ongoing for some time, how could he still be in Bavaria?"
"I, however, believe this intelligence is highly credible," the Margrave of Baden slammed his fist on the table, splashing wine onto the map spread out. "Rather, the fact that they have remained completely silent during our invasion of Palatinate for over a month, doesn't that prove Palatinate's forces are depleted?
I also heard that the Duke of Landshut still intends to target the Imperial Free Cities within his territory and is preparing for war with the Margrave of Ansbach.
Besides, with our current formidable strength, we don't need to concern ourselves with the veracity of this intelligence.
The lands on both banks of the Rhine River should rightfully be under our control.
For too long, we have been constrained by the Elector Palatine. If not now, when will we seize this opportunity to break the deadlock?
In my opinion, we should directly attack Heidelberg tomorrow and seize the Elector Palatine's home.
If we're lucky, we might even capture the deposed young Elector, and then Frederick, that old bachelor, will have no choice but to surrender."
Upon hearing this, Adolf and the Count of Württemberg and his son all expressed agreement, their eyes gleaming with avarice.
Bishop George of Metz, who was also the brother of the Margrave of Baden and the Archbishop of Trier, clutched the crosier in his hand, the metallic touch calming him.
He said with some concern, "A rash advance, if ambushed, would have unimaginable consequences.
Furthermore, even if we advance, we should do so along the Rhine River. With our current forces, trying to capture Heidelberg is akin to a fool's dream. It would be better to quickly take Mainz and end this war."
The Margrave of Baden waved his hand impatiently: "George, you are always so timid. I always opposed father sending you and John (the Archbishop of Trier) into the church.
You must know that our military actions are supported by the Emperor and the Pope. God's power is with us,
and victory will surely be ours!"
"Well said!"
Archbishop Adolf immediately led the applause, then vigorously praised the Margrave of Baden's faith and courage.
Under their strong instigation, everyone finally reached a consensus, deciding to gather their twelve thousand troops from Bretten and advance north along the Rhine River, bypassing Heidelberg to strike directly into the heartland of Palatinate.
Once they fought their way through Palatinate, they would reach Mainz. What would Dieter use to stop their powerful army then?
Florian, the Imperial Army commander who had been sitting by, watching the debate, still frowned. The entire matter felt strange from beginning to end.
He couldn't verify whether Adolf's intelligence was true, but the sense of crisis brought by his intuition made him decide to play a small trick—he requested Adolf to let the Imperial Army march as the rearguard.
Adolf considered for a moment before agreeing to his request.
The next day, the allied forces left Bretten and advanced northwest, heading directly for Mannheim, located at the confluence of the Rhine River and the Neckar River.
However, this high-spirited army could never have imagined that their every move was under the surveillance of the Elector.
Soon, scouts sent the intelligence back to Heidelberg.
From the watchtower of the Elector's palace, Frederick I held a map in his hand, but his gaze was fixed on the surging war clouds in the distance, his expression grave.
His bodyguard commander, Hans von Gemmingen, rushed over, his footsteps echoing in the empty tower.
"Your Excellency the Elector, the enemy has moved, exactly as you predicted. They are advancing along the Rhine River," Hans's expression held a mix of tension and delight. "We have already set up an ambush near the forest of Seckenheim, and the reinforcements from Mainz have arrived and are waiting according to plan."
Frederick nodded slightly, his gaze as sharp as an eagle's. He sneered, "Adolf is too eager for quick success. That false intelligence will surely make him drop his guard.
Furthermore, since the enemy has come out in full force this time, as long as we seize the opportunity, we will surely defeat them in one blow.
You go to Seckenheim first to coordinate the army. Order the entire army: no one is allowed to act without my command. Those who disobey will be executed immediately. I will follow shortly."
"Yes, Your Excellency."
Frederick took one last look at Heidelberg, shrouded in the clouds of war, and silently prayed for the war to end soon.
After bidding farewell to his nephew Philip, Frederick led a dozen knights and galloped towards the Seckenheim forest on the outskirts of Mannheim, preparing to command the eight thousand Palatinate-Mainz allied forces ambushed there to resist the formidable Imperial Army.