Intertextuality in Biondo's works

Few days ago, I noticed a small, but quite interesting piece of information while researching a copy of the first decade of Biondo (Vat. Lat. 1936). The scribe of the copy had the habit of copying everything from the model, even marginal texts and colophons. He also copied a certain marginal note in the seventh book on f. 120r, which raised my eyebrows:

Luceolim co(e)ptum postea hui(c) et in Italia desc(ri)psi : fuisse : ubi nu(n)c pons est luceolis dictus oppido p(ro)xim(us) Canthiano, Urbinu(m) int(er) et Eugubiu(m) civitates. In vetustissima oli(m) flaminia via.

First, the use of first person singular caught my eye, because other marginal notes are more in the vein of third person narration. Second, I wondered why the scribe would want to tell his own opinion suddenly, when usually he just settled for copying the margins. Then it hit me. The phrase: "Having begun [to describe] Luceoli later in this [book] and I have [also] described it in Italia" did not make sense until I understood the meaning of the word Italia. It refers to Biondo's other work Italia illustrata, in which he describes the topographical layout of ancient Italian peninsula. 

So, the marginal note (and probably the whole manuscript) is actually copied from the original copy of Biondo. This realization alone was significant and changed the way I handled the copy, but it had also larger meaning regarding Biondo's works. They were linked. Naturally I wanted to go to see if Biondo was telling the truth and went to his Italia illustrata. And there, in the section, which dealt with the area of Picenum, there was a text:

[...] quod tamen ex Luceolis oppidi vetusti propinquo loco, qua(m) ex via flaminia Eugubiu(m) est iter a longobardis excisi, ruinis aedificatu(m) fuisse, non dubito. Estq(ue) Luceolis locus ad que(m) libro historiaru(m) septimo ostendimus Narsetem eunuchum castra habuisse quando mors Totilae sibi fuit nuntiata.

Indeed, Biondo had dealt with Luceoli in his Italia illustrata, and the description is very similar to the one in Decades marginal note, although it continues more deeply in the Italia illustrata. However, what struck me even more was the latter part of the quote where Biondo tells that "Luceoli is the place to which, as I have shown in the seventh book of the Histories, Narses the eunuch had built a fortress when he was informed of Totila's death." In it Biondo clearly refers back to his Decades, to the seventh book, where the marginal note was from. In the main text beside the note, this event is dealt in length.

Consequently, Biondo wanted the readers of his topographical work to look for deeper historical information regarding a certain area from the Decades. And reciprocally the readers of the historical work could look the deeper topographical information from the Italia illustrata. It can then be suggested that Biondo intended his works to be read as a set. One should always be able to check the necessary information quickly, because he had all the works.