A process for preparing a composite, ultra-refractory, fibre-reinforced ceramic material comprising: (i) infiltrating a plurality of fibres selected from carbon fibres, silicon carbide fibres and combinations thereof, with a ceramic suspension, thereby obtaining an infiltrated composite material, and drying the infiltrated composite material, wherein the ceramic suspension comprises: a mixture of solid ceramic phases comprising: (a) 55-96 vol.% of an ultra-refractory ceramic component selected from the group consisting of ZrB 2, HfB 2, TaB 2, TiB 2, NbB 2, ZrC, HfC, TiC, NbC, TaC and mixtures thereof; (b) 2-30 vol.% of SiC; (c) 0.1-15 vol. % of at least one compound selected from the group consisting of oxides, borides, borates and hydrides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, preferably selected from the group consisting of the oxides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, more preferably is yttrium oxide; the sum of volumes (a)+(b)+(c) being equal to 100 vol.%; and a dispersant selected from the group consisting of water, organic solvents, liquid organic precursors of SiC, liquid organic precursors of carbon and mixtures thereof; (ii) consolidating the dried composite material at a temperature comprised in the range 1700° - 2000°C. (i) infiltrating a plurality of fibres selected from carbon fibres, silicon carbide fibres and combinations thereof, with a ceramic suspension, thereby obtaining an infiltrated composite material, and drying the infiltrated composite material, wherein the ceramic suspension comprises: a mixture of solid ceramic phases comprising: (a) 55-96 vol.% of an ultra-refractory ceramic component selected from the group consisting of ZrB 2, HfB 2, TaB 2, TiB 2, NbB 2, ZrC, HfC, TiC, NbC, TaC and mixtures thereof; (b) 2-30 vol.% of SiC; (c) 0.1-15 vol. % of at least one compound selected from the group consisting of oxides, borides, borates and hydrides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, preferably selected from the group consisting of the oxides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, more preferably is yttrium oxide; the sum of volumes (a)+(b)+(c) being equal to 100 vol.%; and a dispersant selected from the group consisting of water, organic solvents, liquid organic precursors of SiC, liquid organic precursors of carbon and mixtures thereof; a mixture of solid ceramic phases comprising: (a) 55-96 vol.% of an ultra-refractory ceramic component selected from the group consisting of ZrB 2, HfB 2, TaB 2, TiB 2, NbB 2, ZrC, HfC, TiC, NbC, TaC and mixtures thereof; (b) 2-30 vol.% of SiC; (c) 0.1-15 vol. % of at least one compound selected from the group consisting of oxides, borides, borates and hydrides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, preferably selected from the group consisting of the oxides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, more preferably is yttrium oxide; the sum of volumes (a)+(b)+(c) being equal to 100 vol.%; and (a) 55-96 vol.% of an ultra-refractory ceramic component selected from the group consisting of ZrB 2, HfB 2, TaB 2, TiB 2, NbB 2, ZrC, HfC, TiC, NbC, TaC and mixtures thereof; (b) 2-30 vol.% of SiC; (c) 0.1-15 vol. % of at least one compound selected from the group consisting of oxides, borides, borates and hydrides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, preferably selected from the group consisting of the oxides of at least one element selected from the group consisting of scandium, yttrium, lanthanum and mixtures thereof, more preferably is yttrium oxide; the sum of volumes (a)+(b)+(c) being equal to 100 vol.%; and a dispersant selected from the group consisting of water, organic solvents, liquid organic precursors of SiC, liquid organic precursors of carbon and mixtures thereof; (ii) consolidating the dried composite material at a temperature comprised in the range 1700° - 2000°C.