According to historian Michael Kulikowski, sometime in the spring of 402 Alaric decided to invade Italy, but no sources from antiquity indicate to what purpose. Burns suggests that Alaric was probably desperate for provisions. Using Claudian as his source, historian Guy Halsall reports that Alaric's attack actually began in late 401, but since Stilicho was in "Raetia" "dealing with frontier issues" the two did not first confront one another in Italy until 402. Alaric's entry into Italy followed the route identified in the poetry of Claudian, as he crossed the peninsula's Alpine frontier near the city of Aquileia. For a period of six to nine months, there were reports of Gothic attacks along the northern Italian roads, where Alaric was spotted by Roman townspeople. Along the route on "Via Postumia", Alaric first encountered Stilicho.