Abruzzi, also called Abruzzo, was a hill town in the Middle Ages. It was an agricultural economy, relying on livestock, farming, shepherds, etc. This is where Euthansia is wandering after her younger brother dies: 

"You have not studied the histories of ancient times, and perhaps know not the life that breathes in them; a soul of beauty and wisdom which had penetrated my heart of hearts. When I descended the hills of Abruzzi, and first saw the Tiber rolling its tranquil waters glistening under the morning sun; I wept" (149).

After gaining monetary support in Holland/Flanders, Castruccio journeys to the French camp where he finds Scoto. (98)

Here we see Castruccio really begin his journey into warfare and what will eventually put him fully at odds with Euthanasia (and what will keep them fatally irreconciable).

While traveling with Pepi, the two pass through Turin. Shortly before this, Pepi gives his speech against Liberty and, when they are in Turin, Castruccio and him part ways. (114-115)

Castruccio takes part in a hawking party in Chelsea. Tempers flair, and one of the nobles strikes Castruccion in the face after a sarcastic remark. Castruccio replies "by blood, and not by words, are blows to be avenged!" then "drew his stiletto, and plunged it into the bosom of his adversay" (95). King Edward saves him from retribution, but send him to a vessel headed to Holland by way of the Tower. The barons seize Alderigo, intending for him to take the punishment before Edward pardons him.

King Edward sends Castruccio (by way of Bristol and Cork) to Dublin. Piers Gavaston was in exile, and Castruccio was to bring him back to England. (Page 93). Gavsaton was a fascinating medieval figure. He was close friends with King Edward, who made him Earl of Cornwall, despite his humble background. Gavaston was extremely disliked by the nobles, who conspired to have him exiled on three different occasions. Finally when in 1312 when fighting broke out between the barons and the king, Warwick and Pembroke captured Gavaston, and executed him.

In 1309, Castruccio arrives in London, where he meets his cousin Alderigo. Castruccio soons finds favor with King Edward, which gains him the ire of the other nobles of the court. (Page 88).

After killing a Venetian noble, Castruccio flees Venice for Holland. The ship on which he flees first lands at Ostend (Valperga 96), which (in Castruccio's time) is a coastal "fishing village" (Britannica.com). This is where Castruccio meets an unnamed "rich merchant of Ostend, living in the Italian style, and surrounded by a family, whose language and persons transported him to the plains of Lombardy, or the vallies of his native Tuscany" (97).

Image - Este Castle

Castruccio and Guinigi pass through Padua on their way to Venice. They mention crossing Monte Selice, which must be an English translation, for I had trouble finding evidence of it. (Update - the translation in Italian is Monselice, and exists near Padua... Thanks Cate!!!) Through Gurinigi's eyes, Castruccio really appreciates the beauty surrounding him during this trip. Venice has "streets paved with the eternal ocean, its beautiful domes and majestic palaces" (83). 

 Monselice picture below!