The Friar and the Nun
for a line of as many couples as will.
Reconstructed by Dafydd Cyhoeddwr.
This is a standard first edition progressive dance with an intro figure and two progressive figures.  The regular formula (n-1)x3 applies for each of the progressive figures, plus one for the intro.
So, 3 couples = 13 repeats, 4 couples = 19 repeats, 5 couples = 25 repeats.
Music: St Cecilia, Volume 1, among others - none have quite enough repeats
iTunes building blocks
Intro (1 repeat)
1&2: Men go forward a double, then turn single (left)
3&4: Women go forward a double, then turn single (left)
5&6: Women face down, go forward a double, turn single (right)
7&8: Men face down, go forward a double, turn single (right)
First progressive figure:
1&2: Man 1 and man 2 take inside hands and fall back a double, drop hands and turn single (left)
3&4: Woman 1 and woman 2 take inside hands and fall back a double, drop hands and turn single (left)
5&6: Couple 1 and couple 2 double forward and switch (by right shoulders) in two doubles
7: Man 1 and man 2 switch along the line by left shoulders in 1 double at the same time as woman 1 and woman 2 do the same
8: Couple 1 and couple 2 switch places (by right shoulders) in 1 double to return to the proper side of the set
R: Continue switching to the bottom or top of the line, sit out a repeat, and come back in as the opposite type.  Continue until everyone is back to where they started, when the second figure can begin.
Alternatively, once couples 1 and 2 are back where they started, they can start the second figure - this works best with live musicians since it changes the number of required repeats.
Second progressive figure:
1: Man 1 and man 2 switch places by both hands in one double - don't drop hands
2: Woman 1 and woman 2 switch places by both hands in one double - don't drop hands
3: These sets of two take 4 slips into the center to meet shoulder to shoulder
4: Everyone drop hands and turn single
5&6: Take hands in a circle and go halfway around in 4 slips, drop hands and turn single
7&8: Take (right) hands across and finish the circling in a double, drop hands and turn single
R: Continue switching to the bottom or top of the line, sit out a repeat, and come back in as the opposite type.  Continue until everyone is back to where they started, and the dance is finished.