Utraquism

Utraquism (from the Latin sub utraque specie, meaning "under both kinds"), also called Calixtinism (from chalice; Latin: calix, borrowed from Greek kalyx, "shell, husk"; Czech: kališníci), was a belief amongst Hussites, a reformist Christian movement based on the Czech lands, that communion under both kinds (both the consecrated host and the precious blood, as opposed to the consecrated host alone) should be administered to the laity during the celebration of the Eucharist.

[3]: 51  There is disagreement in sources about whether he, or early Utraquists, taught this was necessary for salvation[4]: 180  (as claimed by Catholic detractors such as Andrew of Brod), or necessary to receive the salvific effect of the eucharist[4]: 174  or an obligation.

[5]: 518 The 15th century Utraquists were a moderate faction of the Hussites with strong respect for the sacrament and, generally, endorsed transubstantiation and Catholicity[6] (in contrast to the more radical Taborites, Orebites and Orphans who were closer to the beliefs of John Wycliffe).

[2] The Utraquists eventually allied themselves with the Catholic forces (following the Council of Basel) and defeated the more radical Taborites and Orphans at the Battle of Lipany in 1434.

[2] After that battle, nearly all forms of Hussite revival were Utraquist, as seen with George of Poděbrady, who even managed to cause the town of Tábor, the famous Taborite stronghold, to convert to Utraquism.