Pattabhi Jois, The Last Man Standing
Indra Devi was probably the first foreigner as well as the first woman to be taught by Krishnamacharya, at his time teaching at the Mysore Palace. However, she never taught (in a direct sense at least) what she learnt from him.
As for BKS Iyengar, he was sent to Pune to teach by K at the age of nineteen, after only the briefest period of being taught asana by Krishnamacharya (he claims he only ever received literally two lessons from K). In fact, his asana method could almost be classed as a reaction against K’s teaching.
Finally, we have Desikachar, Krishnamacharya’s son, but he was taught by his father much later when he dramatically altered his teaching and approach.
It was only Pattabhi Jois who carried on the original mantle of K’s teaching at this time.
 He always claimed he continued to teach exactly as he had been taught. This an unlikely assertion, as K seems to have, even at this time, been much more amenable to individual adaption regarding the sequencing/vinyasa aspect than Jois was. On the other hand, it has been mooted by a number of people that Jois may well have been the last man standing in terms of his continued practice with Krishnamacharya over the period of the Mysore Palace. This must count for something then, regarding the continued lineage aspect that Pattabhi Jois always claimed to pass down.
Indeed, his sticking power may be a somewhat unusual occurrence; impressive in the context of what we have been passed down about K’s teaching at this time. Indeed, it is well known that Krishnamacharya was a hard taskmaster, both in terms of discipline as well as his physical adjustments..
This may then be the reason why we really know so little of exactly how K was teaching in these early years; there were so few people who survived to tell the tale. Of course, Krishnamacharya was later to teach notable teachers such as A.G Mohan, his son (TKV Desikchar) and Srivatsa Ramaswami, who were much more vocal about his teaching. One more reason why the absence of voices regarding his early years is all the more noteworthy.
Again, as BKS Iyengar was more than forthright in doing, Pattabhi Jois himself also appears to corroborate the unforgiving nature of K’s early teaching. He would often tell stories of legendary adjustments by Krishnamacharya; one of which involved K standing on him whilst Jois performed kapotasana.
He then gave a lecture on philosophy to the crowd assembled for the yoga demonstration. With this as an example then, it is highly unsurprising that other than Pattabi Jois we only know of a handful of others practising at that time. Perhaps, however, even more, so that both Iyengar and Jois always to refer to Krishnamacharya as their guru.
Then, as far as is currently known, there was also Mahadev Bhatta, Keshyamurthi/, and Dr TRS Sharma. Bhatta appears to have taught in Mumbai, passing away in the late eighties. Keshyamurthi/y seems to have vanished. Dr TRS Sharma is still living, educated in America and a professor and teacher of English literature I believe for all his life.
However, the one other person who can give an alternative narrative to that of Pattabhi Jois, hardly remembers Jois’ presence at the time they were all studying under K. On the other hand, he still also refers to Krishnamacharya as his guru and particularly emphasizes the importance of the aspect of vinyasa in his teaching.
Nevertheless, it is perhaps strange how he doesn’t remember Jois. For, due to Jois’ general robustness and endurance, it appears he was put in charge of leading the yoga demonstrations regularly given by K’s students at the time. Hence, the theory of how we get Jois’ Ashtanga from K’s Yoga Korunta seems to be that the more individualized approach of K whilst teaching at the Mysore palace, was sequentiality to suit the requirements of a demonstration.
As was the trend at the time, everyone performing at the demonstration (the young Brahmin boys at the time) was to perform a synchronized practice together. Accordingly, it is generally agreed that Pattabhi Jois’ Ashtanga yoga is a codified version of Krishnamacharya's original, more individually based, teaching, and one that they perhaps evolved together as Pattabhi Jois led the demonstrations for K.
Krishnamacharya in his Yoga Makarananda (1934), does elaborate on a series that roughly resembles the standing sequence, progressing to a similar beginning to the seated series of Pattabhi Jois’ Primary Series.
However, there is not enough similarity to suggest that Jois’ series were directly those taught to him by K. Otherwise, why would he not be stringent about the exact sequences in his only text on asana, when he is particularly around the following of a specific vinyasa in entering and exiting the postures.
Nevertheless, the postures detailed in the text area are certainly known to us, comprising Primary, Intermediate and Advanced series asana. The very way that they are generally performed is very different to what we recognize in today’s Ashtanga yoga. 
Along these lines, the strict adherence to set sequences and their specific vinyasa does then function to differentiate what K originally taught as opposed to what Jois ended up teaching. Even though both had a specific interest in the importance of vinyasa in asana, it was Jois who also emphasized this particular and most generalized version of what Krishnamacharya would later refer to as vinyasa krama. 
 He did begin by practising what looks very like Ashtanga in the vinyasa method and there are a few very early videos (1938) of him practising along, very proficiently, with K (however, the order is not the same as in Jois’ Ashtanga).
 BNS Iyengar – no relation to BKS- who also teaches in Mysore, is the one other person to teach this method. He claims to have learnt alongside Jois, though teaches a few things slightly differently, saying that Jois had forgotten a few details. He outlives Jois and still teaches in Mysore.
 BKS Iyengar often also told the story of his being made to perform, despite his protestations (he was already injured) hanumanasana for a yoga demonstration by K, at which time he tore his hamstring. An injury which subsequently took him two years to recover from. Indeed, he also mentions that the only time he was trained by Krishnamacharya was on the occasion that his favourite students Keshyamurthy suddenly left without a word.
 The Maharaj of Mysore was strongly involved in the movement for Indian independence, and the idea of an indigenous movement discipline that would build strong young people was a big part of this, hence K’s employment and the importance of promoting this in regular yoga demonstrations.
 All this should give us pause for thought when finding ourselves verging towards dogmatism in the way Ashtanga yoga should be done. Rather, for K it clearly doesn’t appear to be a question of the sequences themselves. The Yoga Makaranda is easily enough found as a pdf through a quick search on the internet.
 Vinyasa Krama is the idea that a sequence of postures has a particular intelligence in its structuring. This became increasingly central to K’s teaching as the years went on. However, we will never know how he used this principle (whether in a generalized way, or in an individual sense as he did later), at the time of his teaching at The Mysore Palace.