The Fight for Tuscany
Prelude
War with Saxony had started back in 1611, when Portugal decided to help their ally, Great Britain, to defend against invasion of the North-German medium power. Long distance, war no-one cared about. Sebastião I was busy with Yemen and Ottomans, so no battles fought or resources wasted. Unfortunately, Portugal got two problems. First, the leadership in the war. And Saxony was doing great, since neither Portugal or Great Britain moved themselves. Second, one of the allies of Saxony was Mantua. Who were neighbours with Tuscany, the Portuguese vassal in Italy.
By May 1614, when the Portuguese war with Yemen ended, Mantua had captured Pisa, the Tuscan port and were sieging Firenze, their capital. Total 12 000 soldiers in the area- not much by far, but still problematic. Portugal needed to transport troops there and the troops were available in armies of 9000 soldiers- the only transport fleet around was capable of taking only 9 regiments at the time. Meaning- 9000 Portuguese would have to fight 12 000 Mantuan troops. Not good.
Siege of Firenze
Sebastião I solved that problem with diplomacy. In the end of summer 1614, Portugal and Papal States signed a treaty, allowing Portuguese use the Papal lands to gather their armies. No agreement was reached over the usage of Papal ports though, so the Portuguese had to keep their navies close to the shore and use the boats to transport men, horses and cannons ashore. A chose, some would say. A logistical nightmare, others would say. “Curse the Pope!” was what people directly involved did say (and that is the nicest thing say said).
Situation in October 1614- Portuguese are ready to march
Despite the problems, Portugal had an army of 18 000 soldiers in Rome by October 1614. The first Portuguese invasion to Italy had begun.
Defeating the Mantuans
In October, the Portuguese marched onwards from Rome. In the end of the October, their quick march took the 3000 Mantuans sieging Firenze by surprised and before any of them understood, they were surrounded and under siege themselves. None walked out alive. After that, the bigger Mantuan army of 9000 soldiers, still happily looting Pisa, also got what they deserved. By the end of November, the Tuscan lands were free of enemy soldiers and Portuguese started a siege to retake Pisa.
The Portuguese destroying Mantuan armies
In April 1615, situation was still quiet in Italy. As for Iberia- another ally of Saxony, Trier, mustered a small army of 7000 soldiers and marched them to Iberia. Led by Werner I von Wittelsbach, pfalz count of Trier, the Germans expected a quick victory. As Werner I himself put it: “One German is worth 10 worthless Portuguese”. So, they marched, expecting a quick victory.
To be fair, the enemy did put a surprisingly good fight- but in June 1616, the Germans were forced to run back across the Pyrenees and march all the way back to Trier. Only with little less numbers.
Germans coming, Germans running
In October 1615, Pisa fell and Tuscany was yet again in Tuscan hands. Portuguese destroyed a small Mantuan army trying to retake Florence and then, marched on. In August 1616, Siena and Sardinia fell (yes, Sebastião had sent 7000 soldiers to siege that one as well). That was enough for Mantua. Rest of their provinces were under siege, Mantua had no soldiers left for war and Portuguese gained a upper hand. Demanding only release of Siena in progress, the Mantuans got off easily.
End of Mantuan War
Integration of Tuscany
In November 1616, the newly independent Duchy of Tuscany was that no more. Their rulers accepted the guiding hand of Sebastião I to further protect their country- and who else would protect them better then Portugal, the most powerful nation on Earth?
As for Portugal, they gained their first provinces in Italian peninsula. One of them being Firenze, one of the richest, did not hurt. A good bridgehead for further expansion. And- speaking of further expansion, Portuguese diplomats already formed an alliance with the newly liberated Siena, a royal marriage was arrange and everything else was made ready to replace them as Tuscany in Portuguese Italian vassals.
This is it- Tuscany is Portuguese
On another note, Sebastião I did something to really worsen the Portuguese relations with the French. Then again, the French fleet in Seville had reached to 30 light ships already, taking quite a deal of money Portuguese try so hard to take from the New World and Asia and shipping it on to Bordeaux. This is not very nice- so, also in November 1616, Sebastião I ordered embargo on the French traders in Portuguese ports.
End of War
Finally in November 1616, Sebastião I looked into the situation with the Saxony. Portuguese were still losing the war and did not care enough to do something about it. Marching their troops across Italy, across the Alps and finally across Austria to save a province they did not care about seemed like a waste.
So, Sebastião I sent emissaries to Saxony, signing a peace. It was actually the first defeat Portugal had suffered in war for more then 200 years- Portugal accepted that Saxony had all the right to keep Salzburg and end the life of a nice small nation. Well, that is what you get for getting allies who don’t care and don’t have the means to help you...
Portugal and Great Britain as allies for Salzburg? Not a good idea!
As a final thing, Siena accepted to become vassals of Portugal in December 1616. Expansion into Italy continues... slowly.