  The generation of large multiphoton quantum states - for applications in
computing, metrology, and simulation - requires a network of high-efficiency
quantum memories capable of storing broadband pulses. Integrating these
memories into a fibre offers a number of advantages towards realising this
goal: strong light-matter coupling at low powers, simplified alignment, and
compatibility with existing photonic architectures. Here, we introduce a
large-core kagome-structured hollow-core fibre as a suitable platform for an
integrated fibre-based quantum memory with a warm atomic vapour. We
demonstrate, for the first time, efficient optical pumping in a hollow-core
photonic-crystal fibre with a warm atomic vapour, where (90 $\pm$ 1)% of atoms
are prepared in the ground state. We measure high optical depths (3$\times
10^{4}$) and, also, narrow homogeneous linewidths that do not exhibit
significant transit-time broadening. Our results establish that kagome fibres
are suitable for implementing a broadband, room-temperature quantum memory.
