Synodat'cum or CATHEDRATICUM, is the annual tribute paid by incumbents of benefices in the Church of Rome to the bishop of the diocese, in token of subjection to the episcopal cathedra. It is generally paid at the time of the convening of the diocesan synod. The earliest direct mention of this impost occurs in the transactions of the second Synod of Braga, A.D. 572 (sess. 2, can. 2, in c. 1, cans. 10:qu. 3), where various extortions on the part of Spanish bishops are forbidden, and they are permitted only in connection with the visitations of their districts "honorem cathedra suae id estsduos solidos per ecclesias tollere." The same synod forbids the payment of an impost by candidates for ordination, which is also termed cathedraticum, but must not be confounded with the synodaticum, The seventh Council of Toledo, A.D. 646 confirmed the action of Braga; and Charles the Bald, in 844, directed the payment of two solidi, or an equivalent in kind (Pertz, Monum. Germanice, 3, 378), and devolved this collection for the bishops on the archpresbyters. Pope Alexander III conceded to bishops who should obtain a church from the hands of the laity the right to impose on it the cathedraticum (c. 9, X, De Censibus, 3, 39); and both Innocent III (c. 20, X, De Censibus) and Honorius III (c. 16, X, De Officio Judicis Ordinarii, 1, 31) expressed themselves in favor of its being rendered. Other references may be found in Du Fresne, s.v. "Cathedraticum" and "Synodus;" Benedict XIV, De Synod. Dimceesana,lib. 5, c. 6:1 and 2; Richter, Kirchenrecht (5th ed.), § 233, note 4, etc.; Gudenus, Cod. Diplomat. 1, No. 93, p. 260. The Council of Trent discontinued the payment of many heavy impositions connected with visitations (sess. 24:can. 3, De Reform.); but various declarations of the Congregatio pro. Interpret. Conc. Trident have left the cathedraticum in force (see Ferraris, Bibl. Canon, s.v. "Cathedraticum;" Thomassin,. Vet. ac Nov. Eccl. Discipl. II, 2, 32, 34; Benedict XIV, ut sup. 6 and 7; Declarationes 18-26 in the edition of Trent by Richter and Schulte, loc. cit.). This impost is termed cathedsaticum "in honorem cathedrae," and synodaticum as being collected during the session of synod; but it has in practice been paid at other times as well and is exacted even where noῥ synod is held, unless a custom recognized in law forbids (Benedict XIV, ut sup. etc.). A tax expressive of subordination is required in any case, amounting generally to two solidi. It must be paid by all churches and benefices and their incumbents, and also by seminaries with which benefices are incorporated, and lay unions having a church of their own. Regulars are exempt with reference to convents and convent churches in which they personally minister. The Order of St. John of Jerusalem is likewise exempt. In practice, however, it has not always been possible to collect these taxes. Austria ceased to pay them under imperial rescripts of 1783 and 1802, and in many other districts of Germany they were quietly discontinued. Their validity was decreed in Bavaria, on the other hand, so late as 1841 (see Permaneder, Handb. d. Kirchenrechts, 3rd ed., p. 319, note). —Herzog, Real-Encyklop. s.v.