capital punishment either death or loss of citizenship.
compulsory public service (functio, munus, munia, necessitas, officium). As an integral part of the taxation system, the government imposed upon the people the burden of performing certain public services without remuneration, but ordinary tax payments were often called by this name (munera pecuniaria), since they were the most essential of the compulsory public services.  The burden of these compulsory services fell most heavily on the middle and lower classes.  Some of these services, such as that of various offices in the municipality, were called "honors."  Thus in every municipality the leading citizens were appointed to membership in the municipal council as decurions, and they were compelled to serve their municipalities and the central government in numerous official capacities, at great personal expense and inconvenience, and often to the complete ruin of their fortunes.  The various landholdings were subject to the payment of special services, payments which the land-holders usually imposed on their tenants, though some of these services, such as the collection of recruits for the army and recruit taxes were performed by the landholders themselves.  Other compulsory services of property were the free quartering of soldiers and other members of the imperial service on householders, and the furnishing of various supplies, such as wood, lumber, sand, and other building materials.  In addition, services and supplies were requisitioned for the maintenance of the public post and for services in connection with the transport of troops and supplies for the army.  Especially burdensome were the menial and physical compulsory services, such as limeburning, charcoal burning, and breadmaking. In addition, the lower classes must furnish labor in the State armories, in the mines and quarries, in the construction and repair of public buildings, highways and bridges, and in a vast number of menial tasks that were performed for the socialized State. (Pharr, p. 577).
Note on Constantine's declarations at Nicaea Recorded in:

Eusebius, VC 3.12;
Rufinus, H.e. 10.2;
Socrates, H.e. 1.8;
Sozomen, H.e. 1.17.19;
Theodoret H.e. 1.7.12;
Gelasius, H.e. 2.7.39-41 and 2.8.3;
Cassiodorus, H.e. 2.2.2 and 2.5.7;
Barhadbesabba Arabaia, History (PO 23.207);
Isidorus Mercator, Decr. Coll.;
Gregorius Presbyter, De Conc. Nic. Prim.

These are all explained and translated in Coleman-Norton, Roman State and Christian Church (London: SPCK, 1966) pp. 127-35
 

Passion of Maximian and Isaac For English translation, see Maureen A. Tiley, Donatist Martyr Stories: The Church in Conflict in Roman North Africa, Translated Texts for Historians, vol. 24 (Liverpool 1996), pp. 61-75
Eusebius of Vercelli, opera: Eusebius Vercellensis: Opera quae supersunt, V. Bulhart, ed. in Corpus Christianorum, Series Latina, vol. 9 (Turnhout: Brepols, 1957)..