Lombart was a French Protestant who worked in London through the Interregnum. Despite being the finest engraver in England in these years, much about his life is still obscure. He made his will in Paris on 30 October 1681, when his age was given as 69, and died later that day. This places his birth in 1612/3.

Nothing is known of his training. His early work in France was made for publishers from 1637 to the later 1640s. The first trace of him in England is in 1649, and he was heavily involved in engraving the plates for Ogilby's various publications. He can be followed in London through plates which are usually lettered 'a Londres', and are often dated, until 1660. In 1663 he was certainly back in Paris, where he engraved a dated portrait of Antoine Grammont after Wallerant Vaillant. He remained there for the rest of his life. On 9 October 1673 he was received by the Académie Royale de Peinture (A.de Montaiglon, 'Procès-Verbaux de l'Académie Royale de Peinture', II 1878, p.11), but, since he never completed the 'morceau de réception' that was required of him, he never became a full member. His last dated plate is in 1674.

Lombart quickly established a reputation in London. On 23 June 1653 Evelyn recorded in his diary that Lombart 'a famous graver' visited him to see his collections (although curiously Lombart is not mentioned in 'Sculptura'). In 1654 Lombart engraved many of the plates after Clein's designs for Ogilby's Virgil, as well as the portrait frontispiece of Ogilby himself. In 1660 he made a few plates for Ogilby's Iliad, a double-sheet composition of Adam and Eve in Paradise for Ogilby's Bible, and the frontispiece for Stapylton's Juvenal.