The two weeks of beam test in October 2021 marked an important milestone in the re-commissioning of the LHC after the Long Shutdown 2 (LS2). After almost 3 years of shutdown, first beams were back circulating in the LHC as of October 19, 2021. After one week of setup with pilot bunches, collisions were re-established with nominal bunches at 450 GeV.
This contribution summarises the main findings and achievements of the beam test and highlights their implications for the 2022 run. Operational and organizational aspects are also discussed, in particular the impact of the restrictions due to the Covid-19 pandemic on LHC beam operation.