Breathers are localized structures showing periodic variations in parameters. They are found in various fields of science, and are currently attracting significant research interest in virtue of their relationship with a rich set of important nonlinear phenomena. They have recently emerged as a universal ultrashort pulse regime in passively mode-locked fibre lasers. Here, we reviewed our recent works in this fast-growing field, including the first observation of breathing dissipative solitons and their complexes in mode-locked fibre lasers[1-3], breather explosions[4], and intelligent control of breathers over breathing periods, breathing ratios, and the number of breathers[5]. Finally, fractal dynamics of breathers are also reported[6]. The winding numbers (the ratio between the breathing frequency and the laser repetition rate) exhibit the hierarchy of the Farey tree and the structure of a devil’s staircase. Numerical simulations of a discrete laser model confirm the experimental findings. [1].J. Peng, S. Boscolo, Z. Zhao, and H. Zeng, Science Advances 2019, 5, eaax1110. [2].J. Peng, and H. Zeng, Physical Review Applied 2019, 11, 044068. [3].J. Peng, Z. Zhao, S. Boscolo, C. Finot, S. Sugavanam, D. V. Churkin, and H. Zeng, Laser & Photonics Reviews 2021, 2000132. [4].J. Peng, and H. Zeng, Physical Review Applied 2019, 12, 034052. [5].X. Wu, J. Peng, S. Boscolo, Y. Zhang, C. Finot, and H. Zeng, Laser & Photonics Reviews 2022, 16, 2100191. [6].X. Wu, Y. Zhang, J. Peng, S. Boscolo, C. Finot, and H. Zeng, Nature Communications 2022, 13, 1-10.