It was a free Bergere de France pattern that I modified a bit (such a neat word for all the pain) because the rollneck just didn't seem sophisticated enough next to all these cables.
The pattern (in French) is somewhere here
http://www.bergeredefrance.fr/trico/trico.phtml?id_rubrique=2, called Pull empiècement rond.
Sadly, the blurry photos fail to depict my passionate feelings towards the sweater - how do people take pics of knitted items anyway ?

Some sort of close-up of the collar part (for which I just continued with the cables after they had been decreased somewhat):

EDIT:
Here is my attempt to translate the pattern. You may want to check all the numbers with the original pattern (there you can also see the diagram). I'm sorry for possible mistakes, since I'm tired and have never written a pattern in English, and I'm happy to correct everything you point out (for example, explanations for decreases and increases at sides seem very unclear right now). Feel free to ask anything.
THE CABLED SWEATER FROM BERGERE DE FRANCE
Sizes 1-2-3-4
Materials:
Yarn MAGIC (by Bergere de France),
10-11-12-13 skeins [REMARK: for turtleneck, add 1 skein],
5 mm and 5.5 mm needles,
5.5 mm circular needles,
cable needle,
14 mother of pearl buttons.
Stitch patterns used:
STOCKINETTE using 5 mm and 5.5 mm needles.
RIB PATTERN using 5 mm needles (worked over a multiple of 4 sts + 2):
1st row (right side of work): *k2, p2*, repeat from * to *, finish with k2.
2nd row and all even rows: purl.
Repeat these 2 rows.
CABLES using 5.5 mm needles (6 stitches):
1st row (right side of work): knit.
2nd row and all even rows: purl.
3rd row: sl 1 to cable needle and hold to front of work, k2, k1 from cable needle, k3.
5th row: k3, sl 2 to the cable needle and hold to back of work, k1, k2 from cable needle.
7th row: same as 3rd row [REMARK: So once you get it going, the actual pattern repeat is 4 rows. Which is far less intimidating.].
REVERSE STOCKINETTE using 5.5 mm needles.
Gauge:
For stockinette, 16 stitches and 22 rows using 5.5 mm needles equals 10 x 10 cm.
For cable pattern, 18 stitches and 22 rows equals 10 x 10 cm.
Directions:
BACK:
CO 72-78-84-92 sts, using 5 mm needles. Knit 2 rows stockinette and 4 rows rib pattern as follows:
T.1, T.3 and T.4: k3 instead of k2.
T.2: as explained [i.e, as explained in Rib pattern section above].
Continue in stockinette on 5.5 mm needles and beginning on 3rd row, decrease 1 stitch on each side at 3 stitches from the side every 6th row 6 times.
To dec 1 st at 3 sts from the side:
at right, k3, k2tog; at left, when you have 5 sts left, SKP [=slip 1, knit 1, pass slipped st over; REMARK: I SSK-d everywhere I was told to SKP, that is, slip 1, slip 1, knit into both stitches], k3.
Knit 5 rows in stockinette with 60-66-72-80 remaining sts; then, beginning on row 3, inc 1 st on each side at 3 sts from the side every 6th row 6 times.
71-78-84-92 sts remain.
RAGLAN:
When the work measures 35-36-36-37 cm (78-80-80-82 rows), BO every 2 rows on each side:
T.1: 2 sts once, 1 st once.
T.2: 3 sts once, 1 st 3 times.
T.3: 4 sts once, 1 st 5 times.
T. 4: 4 sts once, 2 sts 3 times, 1 st 3 times.
66 sts remain.
FRONT:
Like the back, but when the work measures 34-36-38-40 cm (74-80-84-88 rows), put on waste yarn 34 middle sts and then on both middle sides every other row 4 times 4 sts.
SLEEVES:
CO 38-40-42-44 sts on 5 mm needles. Knit 2 rows in stockinette and 4 rows in rib pattern as follows:
T.1 and T.3: as explained.
T.2 and T.4: k3 instead of k2.
Continue in stockinette on 5.5 mm needles, at the same time increasing at 2 sts from each side:
T.1: every 14 rows 1 st twice, every 12 rows 1 st 4 times.
T.2: every 12 rows 1 st 5 times, every 8 rows 1 st 5 times.
T.3: every 10 rows 1 st 4 times, every 8 rows 1 st 5 times.
T.4: every 8 rows 1 st 10 times.
50-54-60-64 sts left.
When the work measures 43 cm, decrease every 2 rows on each side:
T.1: 1 st twice.
T.2: 1 st 4 times.
T.3: 2 sts once, 1 st 5 times.
T.4: 2 sts twice, 1 st 5 times.
Put the remaining 46 sts on waste yarn.
YOKE:
Put on 5.5 mm circular needles 46 sts of one sleeve, 66 sts of the front, 46 sts of the other sleeve, 66 sts of the back (= 224 sts), and continue knitting in the round, at the same time on row 1 [REMARK: more like row 0, because this must be before cables start, right? At least that?s how I interpreted it.] decreasing 1 st on each side of each part and increasing evenly 4 sts at the front and at the back and 2 sts on both sleeves. Starting with left sleeve (insert a marker where the round begins; on row 1, the cables must be in the center of each part), knit as follows:
1st row: k15, *p5, 6 cable sts, p5, k41*, repeat from * to * 3 times, p5, 6 cable sts, p5, k26 (=228 sts).
2nd row and all even rows: Knit the sts as they present themselves [i.e, knit or purl].
3rd row: *k2tog, k13, p5, 6 cable sts, p5, k13, SKP, k2tog, k24, p5, 6 cable sts, p5, k24, SKP*, repeat from * to * (=220 sts).
5th row: k14, *p5, 6 cable sts, p5, k39 *, repeat from *to * 3 times, p5, 6 cable sts, p5, k25.
7th row: *k2tog, k12, p5, 6 cable sts, p5, k12, SKP, k2tog, k23, p5, 6 cable sts, p5, k23, SKP*, repeat from * to * (=212 sts).
9th row: k3, *p4, 6 cable sts, p2, p2tog, p1, 6 cable sts, p1, p2tog, p2, 6 cable sts, p4, k17 *, repeat from * to * 4 times, BUT at the end k14 instead of k 17 (=204 sts).
11th row: *k2tog, k1, p4, 6 cable sts, p4, 6 cable sts, p4, 6 cable sts, p4, k1, SKP, k2tog, k12, p4, 6 cable sts, p4, 6 cable sts, p4, 6 cable sts, p4, k12, SKP*, repeat from * to * (=196 sts).
13th and 15th row: Knit as the sts present themselves. Finish row 15 with k15 instead of k13 (beginning of the round moves 2 sts).
17th row: *p1, p2tog, p1, 6 cable sts, p1, p2tog, p1, 6 cable sts, p1, p2tog, p1, 6 cable sts, p1, p2tog, p1, 6 cable sts, p3, 6 cable sts *, repeat from * to * 4 times (=180 sts).
19th, 21st and 23rd row: *p3, 6 cable sts *, repeat from * to * 20 times.
25th row: *p2tog, p1, 6 cable sts *, repeat from * to * 20 times (=160 sts).
27th, 29th and 31st row: *p2, 6 cable sts *, repeat from * to * 20 times.
33rd row: *p2tog, 6 cable sts *, repeat from * to * 20 times.
35th and 37th row: *p1, 6 cable sts *, repeat from * to * 20 times. Finish row 37 with an additional p1 (beginning of the row moves 1 st).
39th row: *5 cable sts, SKP*, repeat from * to * 20 times (=120 sts).
41st row: cont with the cables.
43rd row: *sl 1 to cable needle, hold to front of work, k2tog, k1 from cable needle, k3 *, repeat from * to * 20 times (=100 sts).
45th row: *k2, sl2 to cable needle, hold to back of work, k1, k2tog from cable needle*, repeat from * to * 20 times (=80 sts).
[REMARK: Here begins my modification. Just continue with the cables that are now 4 sts wide and have no purl sts between them, until the collar reaches (almost) desired length, knit 2 rows, knit 4 rows of rib pattern, bind off.]
Knit 5 rows in stockinette, decreasing evenly on the 1st row:
T.1: 9 sts,
T.2: 6 sts,
T.3: 3 sts,
then loosely bind off the remaining 71-74-77-80 sts.
FINISHING:
Sew seams. Sew 14 buttons on yoke between the cables (see photograph).