Massive black holes (MBHs) inhabit galactic centres, and power luminous quasars and active galactic nuclei, shaping their cosmic environment with the energy they produce. The origins of MBHs remain a mystery, and the recent detection by LIGO/Virgo of a black hole of almost 150 solar masses has revitalized the questions of whether there is a continuum between ‘stellar’ and ‘massive’ black holes, and what the seeds of MBHs are. Seeds could have formed in the first galaxies or could be related to the collapse of horizon-sized regions in the early Universe. Understanding the origins of MBHs straddles fundamental physics, cosmology and astrophysics, and bridges the fields of gravitational-wave physics and traditional astronomy. With several existing and upcoming facilities in the next 10–15 years, we foresee the possibility of discovering the avenues of formation of MBHs. This Review links three main topics: the channels of black hole seed formation, the journey from seeds to MBHs, and the diagnostics on the origins of MBHs. We highlight and critically discuss current unsolved problems, touching on recent developments.

大质量黑洞 (MBH) 居住在银河系中心，为发光类星体和活动星系核提供能量，用它们产生的能量塑造它们的宇宙环境。MBH 的起源仍然是个谜，LIGO/Virgo 最近发现了一个将近 150 个太阳质量的黑洞，这让人们重新思考“恒星”和“大质量”黑洞之间是否存在连续体以及种子是什么的问题的 MBH 是。种子可能是在第一个星系中形成的，或者可能与早期宇宙中视界大小区域的坍塌有关。了解 MBH 的起源跨越了基础物理学、宇宙学和天体物理学，并在引力波物理学和传统天文学领域架起了桥梁。在未来 10 到 15 年内，将有几个现有和即将建成的设施，我们预见了发现 MBH 形成途径的可能性。本综述将三个主要主题联系起来：黑洞种子形成的渠道、从种子到 MBH 的旅程以及对 MBH 起源的诊断。我们强调并批判性地讨论当前未解决的问题，并涉及最近的发展。