Unveiling the first black holes

The detection of accreting supermassive black holes at early epochs when the universe was less than a Gyr old has posed a timing challenge for theoretical models of the formation of the first black holes. Starting from stellar remnants of the first stars requires fine tuning to assemble a billion solar masses so swiftly. Massive initial seeds, formed either from direct collapse of gas in pre-galactic disks or from rapidly amplified growth of light seeds can help alleviate this crunch. I will discuss these two formation channels, and how they can be distinguished. Infra-red observations with detectors aboard the upcoming James Webb Space Telescope and detection of gravitational waves from mergers at early times by the planned LISA mission offer tantalizing possibilities for discriminating between current theoretical models and offering new insights into the formation, fueling and growth of the first black holes.