What dog breed is the smallest of the sighthounds?

The Italian Greyhound is the smallest of the sighthounds, typically weighing about 3.6 to 6.8 kg and standing about 33 to 38 cm tall at the shoulder. The breed is believed to have originated more than 2,000 years ago. Dogs similar to Italian Greyhounds are recorded as having been seen around the Emperor Nero's court in Rome in the first century AD.