Context :

Aims : Our aim is to obtain high-accuracy measurements of the physical and orbital parameters of two evolved eclipsing binary systems , and to use these measurements to study their evolutionary status .
We also aim to derive the distances to the systems by using a surface brightness–colour relation and compare these distances with the measurements provided by GAIA .

Methods : We measured the physical and orbital parameters of both systems based on V -band and I -band photometry from OGLE , near-infrared photometry obtained with the NTT telescope and the instrument SOFI , as well as high-resolution spectra obtained at ESO 3.6m/HARPS and Clay 6.5/MIKE spectrographs .
The light curves and radial-velocity curves were analysed with the Wilson–Devinney code .

Results : We analysed two double-lined eclipsing binary systems OGLE-BLG-ECL-123903 and OGLE-BLG-ECL-296596 from the Optical Gravitational Lensing Experiment ( OGLE ) catalogue .
Both systems have a configuration of two well-detached giants stars .
The masses of the components of OGLE-BLG-ECL-123903 are M _ { 1 } = 2.045 \pm 0.027 and M _ { 2 } = 2.074 \pm 0.023 M _ { \odot } and the radii are R _ { 1 } = 9.540 \pm 0.049 and R _ { 2 } = 9.052 \pm 0.060 R _ { \odot } .
For OGLE-BLG-ECL-296596 , the masses are M _ { 1 } = 1.093 \pm 0.015 and M _ { 2 } = 1.125 \pm 0.014 M _ { \odot } , while the radii are R _ { 1 } = 18.06 \pm 0.28 and R _ { 2 } = 29.80 \pm 0.33 R _ { \odot } .
Evolutionary status was discussed based on the isochrones and evolutionary tracks from parsec and mesa codes .
The ages of the systems were established to be around 1.3 Gyr for the OGLE-BLG-ECL-123903 and 7.7 Gyr for the OGLE-BLG-ECL-296596 .
We also determined the distance to both systems .
For OGLE-BLG-ECL-123903 this is equal to d = 2.95 \pm 0.06 ( stat . ) \pm 0.07 ( syst . )
kpc , while for the OGLE-BLG-ECL-296596 it is d = 5.68 \pm 0.07 ( stat . ) \pm 0.14 ( syst . )
kpc .
This is the first analysis of its kind for these unique evolved eclipsing binary systems .

Conclusions :