Why and when did Italian replace the letter L with I in certain words?

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I noticed that in Italian, words that in other Romance languages (sometimes English) generally follow the pattern consonant-L-vowel instead replace the L with I. For example: bianco (ES blanco, FR blanc) and related words like imbiancare (FR blanchir) fiasco (FR flasque, EN flask/bottle)

When did Italian change these words, and is there a reason? Is there a name for this process?