Like all Latin poets at the time, he was knowledgeable about and strongly influenced by Greek mythology and literary conventions. He was a polished performer in the conventional style, and belonged to a group of poets which aspired to refresh and modernise it and give it a more distinctively Roman turn. But he also wrote short poems about real life in largely colloquial language.
Many of these are satirical attacks on contemporaries and even Caesar himself: in this mood, Catullus can be very funny, and extremely gross. He is best remembered, however, for his poems about an affair with a woman he calls Lesbia. It is impossible to know for sure whether ancient sources who identified Lesbia as a real married woman called Clodia, who was about ten years older than Catullus, had it right, but the Lesbia poetry is so beautiful and so moving that it is hard to imagine that he made her up.
No contemporary copies of these Latin poets’ work survive, so we are lucky to have them. (Find out more here). In Catullus’s case, all the early manuscripts we have come via just one copy, now lost, the only one to survive from antiquity. That makes it hard to know whether the collection is as Catullus published it. The more scurrilous and obscene pieces may always have been included, though they make an odd contrast with the tender Lesbia poems and the serious literary and political ones. Equally, what we have could have been put together later on by someone who included material that might have had a more restricted circulation in Catullus’s lifetime. We have no way of knowing, but what is clear from references in Virgil, Horace and other writers is that Catullus’s work was well-known and admired for at least the hundred-and-fifty years following his death.