Disclosed are quinolone hydroxamic acid compounds of the general formula (I), wherein the substituents are as defined in the specification. Also disclosed are methods of making compounds of formula (I) and there use as inhibitors of protein kinases and/or histone deacetylases for the treatment of diseases caused by the abnormal activity of protein kinases and/or histone deacetylases, such as cancerous tumours. Examples of a compound of formula (I) are: N1&rsquo-[3-fluoro-4-[[7-[[1-[2-(hydroxyamino)-2-oxoethyl]-4-piperidinyl]methoxy]-6-methoxy-4-quinolyl]oxy]phenyl]-N1-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide N1&rsquo-(4-fluorophenyl)-N1-[4-[[7-[3-[[2-(hydroxyamino)-2-oxoethyl]amino]propoxy]-6-methoxy-4-quinolyl]oxy]phenyl]cyclopropane-1,1-dicarboxamide
