The Chandra LETG and XMM-Newton Spectra of HR 1099

The X-ray luminous RS CVn binary system HR 1099 has been observed on several occasions in the early phases of $\mathit{\text{Chandra}}$ and $\mathit{\text{XMM-Newton}}$. A very hot (up to 40 MK) dominant coronal plasma has been identified from the high-resolution spectroscopic data; cooler plasma is seen down to about 3 MK. We recently obtained 100 ksec in $\mathit{\text{Chandra}}$'s Guest Observer Program to study the corona of HR 1099 with the High-Resolution Camera (HRC-S) and the Low Energy Transmission Grating (LETG) across the complete temperature range above 1 MK. The data provide an unprecedented view of spectral lines and continua at high resolution between 1 and 175 \AA. We present our investigations on the Chandra LETGS observation of HR 1099 into the context of the latest results obtained with XMM-Newton.