The best known of the Italian high street clothing stores is probably Benetton, which was founded in the Veneto region back in 1965. Benetton also own the more upmarket Sisley stores. There are several branches of both shops in Rome.
Other homegrown High Street clothing stores in Rome include teen store Habana (on Via del Corso) and Blunauta, an Italian brand, founded in 1976, that makes clothes in cotton, silk, and cashmere, and has its flagship store in Piazza di Spagna.
The two main department stores in Rome are Rinascente (one on Via del Corso and one in Piazza Fiume) and Coin (near San Giovanni in Laterano).
There's no Gap in Rome, but an American Apparel shop has recently opened on Via dei Serpenti in Monti. Via del Corso has an H&M, a Zara, and a Mango, and there's another Mango on Viale Cola di Rienzo.