The invention comprises azo dyes which have at least one anionic solubilizing group to confer water-solubility and which also contain at least one group of formula <FORM:0929426/IV(a)/1> where p is 0, 1 or 2, one of m and n is 0 and the other 0 or 1, X is CO, SO2, O, S or SO when both m and n are O and CO or SO2 when one of them is 1, R1, R2 and R3 are H or hydrocarbon radicals, which may be substituted, or, when n is 1, R2 and R3 can together form an alkylene radical, Y is a halo-s-triazine radical attached to a C atom of an aryl nucleus of the dye and Z is a methylene group, or a chain of methylene groups which may be interrupted by an O or S atom or by an NH or N-alkyl group, any of which methylene groups may be substituted by a hydroxy group, or by an alkyl group, and any two of which may be joined by an alkylene group. The dyes may be made by condensing di- or tri-halotriazines with an azo dye as defined above where Y is H or by conventional processes of diazotization and coupling. If necessary a halogen atom in the triazine residue of dihalotriazine products may be replaced by reaction with such compounds as ammonia or an organic mercaptan, hydroxy compound or primary or secondary amine. The dyes may be polyazo, e.g. disazo, dyes but monoazo dyes are preferred. Metal complexes, e.g. of Cu, Ni, Cr and Co may be made. Indicated dyes are those containing azobenzene, azonaphthalene, phenylazonaphthalene, phenylazopyrazolone or naphthylazopyrazolone structures as chromophones, and A--->M--->E, A--->Z\sM-A1 and E1\sM-D-->-E where A and A1 are diazotizable aromatic amines, D a tetrazotizable aromatic diamine, E and E1 coupling components, M a coupling component containing a diazotizable amino group and Z a component which will couple twice. A, A1 and D may have one or more azo groups. Representative of specified values for R1, R2 and R3 are methyl, isopropyl, g -hydroxypropyl, b -sulphatoethyl, sulphomethyl, b -carboxyethyl, cyclohexyl, sulphobenzyl, tolyl, naphthyl and aryl groups containing substituents, e.g. sulpho, nitro, chloro, carboxy and alkoxy groups. When R2 and R3 are joined they may provide a piperazyl residue. Representative of indicated values for Z are methylene, propylene, hexamethylene, b -ethylethylene, b -hydroxpropylene, cycloalkylene, C2H4OC2H4, C2H4SC2H4 and C2H4N(CH3)C2H4, Z is preferably a straight chain alkylene residue of 1-3 C atoms. Specified values for the group of the above formula are SO2NHC2H4NH, SO2N(CH3)CH2CH2(CH3), <FORM:0929426/IV(a)/2> Representative of indicated substituents for the halotriazine nucleus are bromine and chlorine atoms, ethyl, tolyl, naphthyl, methoxy, disulphophenoxy, nitrosulphophenoxy, ethylmercapto, phenylmercapto, b -hydroxyethylamino, N-methyl-N-ethylamino, 4-carboxyphenylamino, sulphonaphthylamino, N-b -hydroxyethyl-N-phenylamino, cyclohexylamino, piperidyl, hydroxy, mercapto, thiocyano and sulphonic acid groups. Preferred are dyes of formula <FORM:0929426/IV(a)/3> where E is a coupling component residue, e.g. of a naphthol sulphonic acid, pyrazolone sulphonic acid or an acetoacet (sulphoarylamide) with the azo group m or p to X, and the benzene p nucleus may be substituted, and the Cu, Cr, Co and Ni complexes thereof; dyes of formula <FORM:0929426/IV(a)/4> where X1 is CO or SO2, one R is -N=N-E, E being a coupling component residue, and the other SO3H, COOH or OH and their complexes with Cu, Cr, Co and Ni; dyes of formula <FORM:0929426/IV(a)/5> where X1 is CO or SO2, A is a mono-, di- or tricyclic aryl residue, e.g. phenyl, naphthyl, stilbene, diphenylamine and benzthiazolylphenyl residues, which may have an azo group, the group containing Z being preferably in the 6, 7 or 8 position and an SO3H group may be in the 5 or 6 position, and their Cu, Cr and Co complexes; dyes, including metal complexes, of formula A-N=N-E-N(R1)-X1-Z-N(R3)Y where A is as immediately above, X1 is CO or SO2 and E is the residue of a 5-pyrazolone attached at the 4 position of the pyrazole ring and with a mono- or di-cyclic benzene radical, e.g. phenyl or stilbyl, in the 1-position; dyes, with their metal complexes, of formula A-N=N-E-X1-N(R2)-Z-N(R3)Y where A is as immediately above, X1 is CO or SO2 and E is a 5-pyrazolone attached in the 4-position and containing in the 1-position, a benzene radical to which X1 is attached, dyes of formula <FORM:0929426/IV(a)/6> where A is a di- or tri-sulphonated benzene or naphthalene radical and dyes, including metal complexes, of formula A-N=N-E-SO2-N(R2)-Z-N(R3)Y where A is as in the third preferred class and E is a naphthyl radical with a hydroxyl or amino group o or p to the azo groups. The dyes colour natural and artificial textile materials, e.g. cotton, viscose rayon, wool, silk, cellulose acetate, polyamides, polyacrylonitriles and aromatic polyesters. When colouring cellulosic materials the dyes are preferably applied in conjunction with an acid-binding agent. The dyes are applied to nitrogenous fibres from a mildly alkaline, neutral or acid-bath. Numerous examples are provided of the preparation of the dyes and their use in colouring processes to produce a variety of colour shades. The first Provisional Specification relates to dyes of formula <FORM:0929426/IV(a)/7> where A is a dye residue and each of the NR groups is joined to a C atom of A, n is 1, 2, 3 or 4, R is H or an alkyl group, which may be substituted, X is -S.CS.N(Z1)Z11 where Z1 is H or a hydrocarbon radical, which may be substituted, or a heterocyclic residue, Z11 is a hydrocarbon radical, which may be substituted, or a heterocyclic residue and Z1 and Z11 may be joined to form with the N atom a heterocyclic ring and Y is a halogen atom, a thiocyano group, a mercapto or substituted mercapto group, or a sulphonic acid group. A may be of the azo nitro, anthraquinone or phthalocyanine series. These dyes are described in the Abridgment of Specification 885,059. Specifications 209,723, 298,484, 467,815, 503,609, 772,030, 774,925, 781,930, 785,120, 785,222, 797,946, 805,562, 826,405, 828,353, 836,248, 837,035, 837,990, 838,307, 838,311, 838,335, 838,337, 838,338, 838,340, 838,341, 838,342, 838,343, 838,344, 838,345, 838,728, 842,933, 844,869, 847,635, 849,772, 851,537, 852,120, 852,911, 855,792, 859,198, 863,155, 863,754, 863,758, 864,080, 864,227, 869,279, 872,249, 874,544, 876,092, 876,632, 877,178, 877,249, 878,527, 878,726, 880,393, 905,521, 911,841, 923,886, 923,887 and 927,771 also are referred to.