  We present a multi-wavelength study of the FSRQ CTA 102 using Fermi-LAT and
simultaneous Swift-XRT/UVOT observations. The Fermi-LAT telescope detected one
of the brightest flares from this object during Sep, 2016 to Mar, 2017. In the
190 days of observation period the source underwent four major flares. A
detailed analysis of the temporal and spectral properties of these flares
indicates the flare at MJD 57751.594 has a $\gamma$-ray flux of
(30.12$\pm$4.48)$\times 10^{-6}$ ph cm$^{-2}$ s$^{-1}$ (from 90 minutes
binning) in the energy range of 0.1--300 GeV. This has been found to be the
highest flux ever detected from CTA 102. Time dependent leptonic modelling of
the pre-flare, rising state, flares and decaying state has been done. A single
emission region of size $6.5\times 10^{16}$ cm has been used in our work to
explain the multi-wavelength spectral energy distributions. During flares the
luminosity in electrons increases nearly seventy times compared to the
pre-flare state.
