The diplomatic situation on the Italian peninsula in 1439 was rather complex. Three large alliances kept the region in balance. Two of the alliances had more members than the limit, Milan's and Genoa's. Genoa's was arguably the mightiest, with Tyrol, Wirtemberg, Styria, Venice and lastly Tuscany, Milan's vassal, on their side. It was clear that an aggressive war against Genoa wouldn't be very clever at that point. Further south was the alliance of Modena, Papal States and Naples. Even if Milan had CB against two of them, I decided to let it wait. Instead I tried to vassalize Mantua (+200), and it was an instant success. A few years later the tensions in the area would easy off with the Treaty of Cremona:

Notice the nation in the background!
The following years were spent at mainly watching Milan's neighbours, and expanding trade in Liguria. However diplomatic actions would soon change this. First of all, Naples became vassals of Aragon. They were forced into Aragon's alliance by event (YodaMaster, I don't like this.
), thus making Milan's alliance more powerful. This made Papal States and Modena much more vulnerable to an attack, but sadly I didn't have a CB at the moment. Second of all, both Milan's, Papal States' and Genoa's alliances expired in 1446. Of course, this caused me some headaches; who should I invite? Aragon and Naples were out of the question, as they're too distant. So were Papal States, as they are impossible to vassalize diplomatically. So the choice fell on Mantua, Genoa, Tuscany and Siena. I was a bit unlucky, since I wanted Switzerland in the alliance, but I had renewed a RM with them recently, so no diplomat was available. They were invited to an alliance with some German minors, so Siena took Switzerland's place.
All the messing around with diplomatic actions had to lead to a war.
The long peaceful state ended in 1449 when Mantua went to war against the lone Modena. Modena's army was beaten, and they retreated into Sforza's (a very good Milanese leader) lap. That secured us some valuable warscore. More on that later. Even if this was a "walkover war", it broke the balance in the region. That caused Theodoros (+Venice, Albania and Tyrol) to DoW Genoa. Tyrol went straight for Lombardia, but they were killed there by Sforza (I love that man). However a siege of Tyrol was thwarted by massive attrition losses and an aggressive Albanian army. Sforza went instead after Veneto, which were captured surprisingly fast.

~80 000 men and winter... ouch. Milan had only 2000 men there though.
As the Venetian fleet lacked a port to stay in, they blockaded the straits at Veneto, effectively trapping Sforza and his men. I therefore accepted a peaceoffer of 400 ducats. Genoa didn't get anything of the share, as they tapped out of the war earlier, giving Kerch to Theodoros! Should make it easier to vassalize Genoa down the line. As for Modena, they had been captured by Mantua. I signed a separate peace gaining 50 ducats(!) due to the WS. That was the green light for Mantua to annex them, which they promptly did. I tried to diploannex both Mantua and Tuscany when the war ended, but both refused. That was the third time Tuscany refused, by the way. On the other hand, one year later Siena accepted to become our vassals.
Around 1454 Savoy (+ Berg and Hesse) got into a nasty war against Burgundy and France, where the latter annexed both of Savoy's allies. That caused many nations to DoW France later on. However I wasn't interested in France - Savoy's weak position was more interesting. I didn't have any CB, but BB was at 0 and relations were >100, so I DoW'ed them in autumn 1454 (no allies involved). Since all of their men were busy in France, their capital was captured without interruption by Sforza. However a peacedeal between the French states caused an Savoian invasion of Lombardia. Sforza was sent back to deal with it:
Even if it seems like Sforza is winning, he lost quite badly. I think it was due to poorly synchronized arrivals for the two Milanese armies. Anyway, Savoy did fortunately not manage to capture the capital within the next few months, so Sforza had time to regain morale. In the ensuing battle it was clear that Sforza was the best leader, and so the Savoian army was wiped out. Piemonte was captured shortly after, and 100% WS was secured. However before I could sign a peace treaty, Genoa DoW'ed the beliggerent France. Since they already were at war with half of Europe, the war wasn't so serious as feared. Lyonnais was captured by Milan, while Provence was captured by Mantua. It was time to sign peace: France had to give the Italians 125 ducats, and MA to Milan. Savoy had to cede Piemonte and 150 ducats to Milan, and they also became our vassals. Two successful wars, without breaking too much sweat.
With peace restored, I tried once again to annex Tuscany, but it was once again a fail. However, if one tries long enough, one will succeed. 
Woho!
That was the last happening worth mention during my turn. Both my slider moves were towards centralization. We also got some random and scripted events that changed our sliders - I remember +2 centralization and +1 offensive. Both are good. I also got a Exceptional Year event, but we only got 100 ducats from it.
I invested in Infra 3 until it was reached in the 1450's, then I invested in Trade 3. It is due in 1483. We have only active merchants in Liguria by the way.
It shouldn't be too hard to annex Tuscany now. We're not in a hurry though, as we have enough provinces to fulfill the KoI trigger. Tuscany got a large army too - it would be nice to exploit it some more. Sforza is still around too, so an offensive war or two shouldn't do much harm, even if our BB is 4.2.
Allies and vassals: Genoa (not vassal), Savoy, Siena and Tuscany
LT 3, NT 2, Trade 2, Infra 3
We need a Tax Collector in Romagna. Inflation is at 0.2%

Granada's still going strong. OE as well.
The Save: http://www.savefile.com/files/1945759
phargle and demokratickid: Nice to know that you're following!