Law reports with KB or AC in citation can be read online in either/both the databases below.
All ER reports are only available via LexisLibrary - in the case of Joyce below, you don't have to read both versions: the AC report is considered the more authoritative
R v Lynch  1 KB 444
R v DeJager  AC
R v Ahlers  1 KB 616
R v Casement  1 KB 98
Joyce v DPP  AC 347,  1 All ER 186
In English common law there was also petty treason - for example when a wife killed her husband (but not vice versa), or a servant his/her master/mistress.
High Treason against the reigning sovereign.
Until 1814 the particular heinousness of the crime could mean the convicted traitor suffered hanging, drawing, and quartering.
Remained a capital offence until the bringing into force of the Crime and Disorder Act 1998 c 37 s 36, when replaced by life imprisonment.
Attainder meant that the punishment could extend to the next generation: heirs of traitors could be prevented from inheriting property or titles.
Treason Act 1351 (25 Edw 3 stat 5 c 2)
(a) conspiracy to kill the sovereign, his queen, or the heir apparent;
(b) violating the royal blood line
(c) fighting against the sovereign within the sovereign's kingdoms, helping his enemies
(d) the killing of certain officers of state ( Lord Chancellor, Lord High Treasurer, judges) when they are carrying out their official functions
The Treason Legislation of Henry VIII (1531-1534): Alexander Prize Essay, 1916
I. D. Thornley Transactions of the Royal Historical Society Vol. 11 (1917), pp. 87-123
Some of the subsequent legislation on treasonable offences
Treason Act 1702 (1 Anne stat 2 c 21)
Treason Act 1790 (30 Geo 3 c 48)
Treason Act 1795 (36 Geo 3 c 7)
Treason Act 1814 (54 Geo 3 c 146)
Treason Act 1842 (5 & 6 Vict c 51)
Treason Felony Act 1848 (11 & 12 Vict c 12)
Subject searches to use in SOLO
Treason -- Great Britain -- History
Trials (Treason) -- Great Britain